Disclosed herein are methods and compositions for inactivating CCR-5 genes, using zinc finger nucleases (ZFNs) comprising a zinc finger protein and a cleavage domain or cleavage half-domain. Polynucleotides encoding ZFNs, vectors comprising polynucleotides encoding ZFNs, such as adenovirus (Ad) vectors, and cells comprising polynucleotides encoding ZFNs and/or cells comprising ZFNs are also provided.