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                       [LETTERHEAD OF O'CONNOR CAVANAGH]


                                                                       EXHIBIT 5


                                September 23, 1998


Rural/Metro Corporation
8401 East Indian School Road
Phoenix, Arizona  85251

                  RE:      REGISTRATION STATEMENT ON FORM S-8
                           RURAL/METRO CORPORATION

Gentlemen:

                  As legal counsel to Rural/Metro Corporation, a Delaware
corporation (the "Company"), we have assisted in the preparation of the
Company's Registration Statement on Form S-8 (the "Registration Statement") to
be filed with the Securities and Exchange Commission on or about September 23,
1998 in connection with the registration under the Securities Act of 1933, as
amended, of 2,609,250 shares of the Company's common stock, par value $0.01 per
share, (the "Common Stock") issuable pursuant to the Company's 1992 Stock Option
Plan (the "Stock Option Plan"). The shares of Common Stock issuable pursuant to
the Stock Option Plan are referred to as the "Shares." The facts, as we
understand them, are set forth in the Registration Statement.

                  With respect to the opinion set forth below, we have examined
originals, certified copies, or copies otherwise identified to our satisfaction
as being true copies, only of the following:

                  A.       The Second Restated Certificate of Incorporation of
the Company, as filed with the Secretary of State of the State of Delaware as
amended through the date hereof;

                  B.       The Bylaws of the Company, as amended through the
date hereof;

                  C.       Resolutions of the Board of Directors of the Company
dated September 12, 1997, reserving an aggregate of 2,609,250 shares of the
Company's Common Stock for issuance pursuant to the Stock Option Plan; and
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[O'CONNOR CAVANAGH LOGO]
Rural/Metro Corporation
September 23, 1998
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                  D.       The Registration Statement.

                  Subject to the assumptions that (i) the documents and
signatures examined by us are genuine and authentic and (ii) the persons
executing the documents examined by us have the legal capacity to execute such
documents, and subject to the further limitations and qualifications set forth
below, it is our opinion that the Shares, when issued and sold in accordance
with the terms of the Stock Option Plan, will be validly issued, fully paid and
nonassessable.

                  Please be advised that we are members of the State Bar of
Arizona, and our opinion is limited to the legality of matters under the laws of
the State of Arizona and the General Corporation Laws of the State of Delaware.
Further, our opinion is based solely upon existing laws, rules and regulations,
and we undertake no obligation to advise you of any changes that may be brought
to our attention after the date hereof.

                  We hereby expressly consent to any reference to our firm in
the Registration Statement, inclusion of this Opinion as an exhibit to the
Registration Statement, and to the filing of this Opinion with any other
appropriate governmental agency.

                                              Very truly yours,

                                              /s/ O'Connor, Cavanagh, Anderson, 
                                              Killingsworth, & Beshears