UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D)

OF THE SECURITIES AND EXCHANGE ACT OF 1934

Date of report (Date of earliest event reported): October 6, 2014

HANSEN MEDICAL, INC.

(Exact name of registrant as specified in charter)

800 East Middlefield Road

Mountain View, California 94043

(Address of principal executive offices and zip code)

Registrant’s telephone number, including area code: (650) 404-5800

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 Audit Committee (the “Audit Committee”) of the Board of Directors of Hansen Medical, Inc. (the “Company”) has completed a competitive process to review the appointment of the Company’s independent registered public accounting firm for the 2014 fiscal year. As a result of this process, effective October 6, 2014, the Audit Committee engaged BDO USA, LLP (“BDO”) as the Company’s independent registered public accounting firm. The composition of the Audit Committee remains unchanged as Marjorie L. Bowen, Michael Eagle and Stephen L. Newman, M.D.

Effective October 6, 2014, the Audit Committee approved the dismissal of Deloitte & Touche LLP (“Deloitte”) as the Company’s independent registered public accounting firm.

During the Company’s two most recent fiscal years and through the date of this Current Report on Form 8-K (i) there were no disagreements with Deloitte on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure which, if not resolved to Deloitte’s satisfaction, would have caused Deloitte to make reference to the subject matter in connection with their reports on the Company’s financial statements for such years; and (ii) there were no reportable events, within the meaning set forth in Item 304(a)(1)(v) of Regulation S-K.

Deloitte’s audit reports on the Company’s financial statements for the past two fiscal years did not contain an adverse opinion or disclaimer of opinion, nor were they qualified or modified as to uncertainty, audit scope or accounting principles.

The Company has provided Deloitte with a copy of the disclosures in this Current Report on Form 8-K and has requested that Deloitte furnish it with a letter addressed to the Securities and Exchange Commission stating whether or not Deloitte agrees with the statements related to them made by the Company in this report. A letter from Deloitte is attached as Exhibit 16.1 of this Form 8-K.

Effective October 6, 2014, the Audit Committee engaged BDO as the Company’s independent registered public accounting firm. In addition, during the Company’s two most recent fiscal years and through the date of this Current Report on Form 8-K, neither the Company, nor any party on the Company’s behalf, consulted BDO with respect to (i) the application of accounting principles to a specified transaction, either completed or proposed, or the type of the audit opinion that might be rendered on the Company’s financial statements, and no written report or oral advice was provided to the Company that BDO concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing or financial reporting issue, or (ii) any matter that was subject to any disagreement, as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions thereto, or a reportable event within the meaning set forth in Item 304(a)(1)(v) of Regulation S-K.

(d) Exhibits.

SIGNATURES

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.

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