UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): July 19, 2012

Carter Validus Mission Critical REIT, Inc.

(Exact Name of Registrant as Specified in Its Charter)

4211 West Boy Scout Blvd.

Suite 500

Tampa, Florida 33607

(Address of principal executive offices)

(813) 287-0101

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

The information reported in Item 2.03 of this Current Report on Form 8-K is incorporated herein by reference.

On July 19, 2012, Carter Validus Mission Critical REIT, Inc., a Maryland corporation (the “Company”), Carter/Validus Operating Partnership, L.P., the Company’s operating partnership (“CVOP”), HC-2501 W William Cannon Dr, LLC, a Delaware limited liability company and a wholly-owned subsidiary of CVOP (“HC-2501 Cannon”), DC-19675 W. Ten Mile, LLC, a Delaware limited liability company and a wholly-owned subsidiary of CVOP (“DC-19675 Ten Mile”), KeyBank National Association (“KeyBank”), and Texas Capital, N.A. (“Texas Capital”) amended that certain Credit Agreement dated March 30, 2012 between CVOP and the lenders party thereto, as previously amended (the “KeyBank Loan Agreement”) and a letter agreement by and between CVOP, KeyBank and Texas Capital to increase the secured revolving credit facility from $40,000,000 to an aggregate maximum principal amount of $55,000,000. The amendment also adds Texas Capital as a lender to the KeyBank Loan Agreement.

In connection with these changes, CVOP entered into a revolving credit note payable to Texas Capital, dated July 19, 2012, in the aggregate principal amount of $15,000,000 (the “Revolving Note”). The loan under the Revolving Note shall bear interest at per annum rates equal to either: (a) the London Interbank Offered Rate, plus an applicable margin ranging from 2.50% to 3.50%, which is determined based on the overall leverage of CVOP or (b) a base rate which means, for any day, a fluctuating rate per annum equal to the prime rate for such day plus an applicable margin ranging from 1.25% to 2.00%, which is determined based on the overall leverage of CVOP. In the event of a default, CVOP shall be required to pay a default interest rate equal to the interest rate calculated in accordance with the KeyBank Loan Agreement, plus 5.00% per annum. Additionally, in the event of default the lender has the right to terminate its obligations under the KeyBank Loan Agreement, including the funding of future loans, to accelerate the payment on any unpaid principal amount of all outstanding loans and interest thereon and may seek foreclosure on the properties that are in the collateral pool.

In connection with the amendment, CVOP entered into conforming amendments pursuant to the (a) Second Amendment to Unconditional Guaranty of Payment and Performance from Carter Validus Mission Critical REIT, INC., et al, for the benefit of KeyBank National Association, dated July 19, 2012, (b) Second Amendment to Mortgage by DC-19675 W. Ten Mile, LLC, as Grantor, and KeyBank National Association, dated July 19, 2012, (c) Second Amendment to Deed of Trust, Security Agreement and Assignment of Leases and Rents and Assignment of Lease and Rents from HC-2501 W William Cannon DR, LLC, as Grantor, to KeyBank National Association, dated July 19, 2012, and (d) Second Amendment to Assignment of Leases and Rents by DC-19675 W. Ten Mile, LLC, as Grantor, to KeyBank National Association, as Agent, dated July 19, 2012.

The material terms of the amendment to the Credit Agreement and the documents set forth above are qualified in their entirety by the agreements attached as Exhibits 10.1 through 10.6, respectively, to this Current Report or Form 8-K and incorporated herein by reference.

Forward-Looking Statements

This Current Report on Form 8-K contains forward-looking statements within the meaning of federal securities laws and regulations. These forward-looking statements are identified by their use of terms and phrases such as “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “should,” “will” and other similar terms and phrases, including references to assumptions and forecasts of future results. Forward-looking statements are not guarantees of future performance and involve known and unknown risks, uncertainties and other factors that may cause the actual results to differ materially from those anticipated at the time the forward-looking statements are made. Operating results will be affected by economic and regulatory changes that have an adverse impact on the real estate market and the Company cannot assure you that there will be growth in the value of the Company’s properties. Although the Company believes the expectations reflected in such forward-looking statements are based upon reasonable assumptions, it can give no assurance that the expectations will be attained or that any deviation will not be material. The Company undertakes no obligation to update any forward-looking statement contained herein to conform the statement to actual results or changes in the Company’s expectations.

(d) Exhibits

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.