Exhibit 99.1

NEWMARKET CORPORATION REPORTS IMPROVED SECOND QUARTER AND FIRST HALF 2011 RESULTS

Richmond, VA, August 3, 2011 – NewMarket Corporation (NYSE – NEU) President and Chief Executive Officer, Thomas E. Gottwald, released the following earnings report of the Company’s operations for the second quarter and first half of 2011.

Net income for the second quarter of 2011 improved to $52.3 million, or $3.77 per share, an increase of 31 percent compared to net income of $39.9 million, or $2.69 per share, for the same period last year. For the first half of 2011, net income increased to $101.8 million, or $7.34 per share, an improvement of 24% compared to net income of $82 million, or $5.47 per share, for the first half of 2010. Earnings per share for the second quarter and first half of this year increased 40 percent and 34 percent, respectively, reflecting the additional benefit of the Company’s stock repurchasing activities. See the Summary of Earnings included in this earnings release for additional information.

The continuing improving operating results in our petroleum additives business are reflected in the stronger second quarter and first half 2011 results. For the second quarter this year, petroleum additives operating profit increased to $85.6 million, an improvement of 12 percent over second quarter last year of $76.6 million. Sales of petroleum additives for the second quarter of this year improved to $572.8 million, an increase of 23 percent over sales in the second quarter of last year of $464.9 million including an increase of 11 percent in shipments. Petroleum additives operating profit for the first half of this year increased to $166.2 million, an increase of 13 percent over operating profit for the first half of last year of $147 million. Sales of petroleum additives for the first half of this year reached $1,075.5 million, an improvement of 26 percent over sales in the first half of last year of $854.3 million. Shipments for the first half of this year are up 14 percent over the same period last year.

Petroleum additives results for both the second quarter and first six months of this year primarily reflect continuing earnings improvement in the lubricant additives product line. Petroleum additives operating profits for the first half of this year have improved in every major region of our operations. Our business is performing well as we increase our investment in R&D to create new innovative products and solutions for our customers such as the recently announced new gasoline performance additives that prevent deposits in DIG injectors. Our business continues to experience the adverse effects of increasing raw material cost which we are working to recover in the marketplace.

During the second quarter of this year, we repurchased 26,500 shares of our common stock bringing the total repurchases in the first half of this year to 217,073 common shares at an average cost of $129.79 per share.

We are pleased with the performance of our business for the first half of this year. The fundamentals of our business are strong, and we are well positioned to service our customers with the innovative products and services that enhance their position to succeed in the marketplace.

Please read our second quarter Form 10-Q for more details on the operations of the company.

Sincerely,

Thomas E. Gottwald

Summary of Earnings for the 2011 and 2010 Periods

Net income for the second quarter and first six months of both 2011 and 2010 included a charge on an interest rate swap agreement related to financing on Foundry Park. These amounts result from the Company valuing the swap agreement at its fair value.

The Company is reporting net income including these amounts, as well as income excluding them, and related per share amounts in this Summary of Earnings. The Company believes that even though income excluding these amounts is not required by or presented in accordance with generally accepted accounting principles (GAAP) accepted in the United States, this additional measure enhances understanding of the Company’s performance. The Company believes presenting our earnings excluding this item enhances period to period comparability. The Company believes that income, excluding this item, should not be considered an alternative to net income determined under GAAP. The following table is a reconciliation of net income under GAAP to net income excluding the losses on the interest rate swap agreement.

As a reminder, a conference call and Internet webcast is scheduled for 2:00 p.m. EDT on Thursday, August 4, 2011, to review second quarter 2011 financial results. You can access the conference call live by dialing 1-877-407-6180 (domestic) or 1-201-689-8050 (international) and requesting the NewMarket conference call. To avoid delays, callers should dial in five minutes early. The call will also be broadcast via the Internet and can be accessed through the Company’s website at www.NewMarket.com or www.investorcalendar.com. A

teleconference replay of the call will be available until August 11, 2011 at 11:59 p.m. EDT by dialing 1-877-660-6853 (domestic) and 1-201-612-7415 (international). The account number is 286. The conference ID number is 375371. A webcast replay will be available for 30 days.

NewMarket Corporation through its subsidiaries, Afton Chemical Corporation and Ethyl Corporation, develops, manufactures, blends, and delivers chemical additives that enhance the performance of petroleum products. From custom-formulated chemical blends to market-general additive components, the NewMarket family of companies provides the world with the technology to make fuels burn cleaner, engines run smoother and machines last longer.

Some of the information contained in this press release constitutes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Although NewMarket’s management believes its expectations are based on reasonable assumptions within the bounds of its knowledge of its business and operations, there can be no assurance that actual results will not differ materially from expectations.

Factors that could cause actual results to differ materially from expectations include, but are not limited to: availability of raw materials and transportation systems; supply disruptions at single sourced facilities; ability to respond effectively to technological changes in our industry; failure to protect our intellectual property rights; hazards common to chemical businesses; occurrence or threat of extraordinary events, including natural disasters and terrorist attacks; competition from other manufacturers; sudden or sharp raw materials price increases; gain or loss of significant customers; risks related to operating outside of the United States; the impact of fluctuations in foreign exchange rates; political, economic, and regulatory factors concerning our products; future governmental regulation; resolution of environmental liabilities or legal proceedings; inability to complete recent or future acquisitions or successfully integrate recent or future acquisitions into our business and other factors detailed from time to time in the reports that NewMarket files with the Securities and Exchange Commission, including the risk factors in Item 1A, “Risk Factors” of our 2010 Annual Report on Form 10-K, which is available to shareholders upon request.

You should keep in mind that any forward-looking statement made by NewMarket in the foregoing discussion speaks only as of the date on which such forward-looking statement is made. New risks and uncertainties come up from time to time, and it is impossible for us to predict these events or how they may affect the company. We have no duty to, and do not intend to, update or revise the forward-looking statements in this discussion after the date hereof, except as may be required by law. In light of these risks and uncertainties, you should keep in mind that the events described in any forward-looking statement made in this discussion, or elsewhere, might not occur.

FOR INVESTOR INFORMATION CONTACT:

David A. Fiorenza

Investor Relations

Phone: 804.788.5555

Fax:     804.788.5688

Email: investorrelations@newmarket.com

NEWMARKET CORPORATION AND SUBSIDIARIES

SEGMENT RESULTS AND OTHER FINANCIAL INFORMATION

(In millions except per share amounts, unaudited)

NEWMARKET CORPORATION AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF INCOME

(In thousands except per share amounts, unaudited)

Notes to Consolidated Statements of Income

NEWMARKET CORPORATION AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS

(In thousands, unaudited)

NEWMARKET CORPORATION AND SUBSIDIARIES

SELECTED CONSOLIDATED CASH FLOW DATA

(In thousands, unaudited)