EXHIBIT 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (No. 333-146176, No. 333-130001, No. 333-152903, No. 333-123778, No. 333-75531, No. 333-57006, No. 333-57008, No. 333-57010, No. 333-57012, No. 333-161307) of Varian Medical Systems, Inc. of our report dated November 25, 2009 relating to the consolidated financial statements, financial statement schedule and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/S/ PRICEWATERHOUSECOOPERS LLP

San Jose, California

November 25, 2009