Studies of the role of tumor suppressor genes in human renal cell carcinoma from our laboratory have suggested the presence of a disease gene(s) on the short arm of chromosome 3. Little is known about the role other tumor suppressor genes may play in this malignancy. Abnormalities of chromosome 17p and, in particular of p53, are common in many human malignancies. In order to evaluate the role of this region in renal cell carcinoma, we performed restriction fragment length polymorphism analyses of chromosome 17 with probes localized to the p53 region. Fourteen of 29 (48%) evaluable cell lines showed loss of heterozygosity at this locus. Northern blot analysis did not detect a p53 transcript in 4 of 27 cell lines tested. In addition, we screened cell lines for p53 mutations using a polymerase chain reaction-single strand conformation polymorphism technique. Cell lines positive for mutations by this technique were then sequenced. Mutations were detected in 11 of 33 (33%) cell lines, including 8 derived from primary tumors and 3 derived from metastatic foci. Six of 9 (67%) patients with loss of heterozygosity demonstrated a mutation in the remaining allele, while only 1 of 8 (13%) without loss of heterozygosity had a mutation. Three of 3 (100%) cell lines derived from metastases had the same mutation as their matched primary cell line. Loss or mutation of p53 did not correlate either with loss of chromosome 3p or with histological subtype. These results suggest that, while the primary disease gene for kidney cancer appears to be on chromosome 3, abnormalities of p53 are common and may be involved in the progression of this malignancy.