EXHIBIT 32.2

CERTIFICATION

PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

(SUBSECTIONS (a) AND (b) OF SECTION 1350, CHAPTER 63 OF TITLE 18,

UNITED STATES CODE)

In connection with the Annual Report of Rural/Metro Corporation, a Delaware corporation (the “Company”) on Form 10-K for the period ended June 30, 2005, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Michael S. Zarriello, Senior Vice President and Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to my knowledge:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in this Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Dated: September 28, 2005

/S/    MICHAEL S. ZARRIELLO        

Michael S. Zarriello

Senior Vice President and Chief Financial Officer

(Principal Financial Officer)