Nearly all clear cell renal cell carcinomas (RCCs) exhibit loss of alleles on the short arm of chromosome 3. Loss and mutation at the von Hippel-Lindau (VHL) gene at 3p25 probably occurs in most RCCs and, since the VHL gene was recently cloned, data on VHL involvement in RCCs is accumulating. However, the region 3p14-p12, a region that contains the familial RCC-associated t(3;8)(p14.2;q24) chromosome translocation and the small cell lung carcinoma-associated homozygous deletion at 3p13-12, has also been reported to exhibit allele loss in a large fraction of RCCs. In order to focus future studies on potential suppressor genes in the 3p14-p12 region, we have studied allele loss in 30 RCCs with 9 polymorphic simple sequence repeat markers spanning 3p21.1-p12. Partial losses in the 3p21-p12 region were observed, allowing determination of common regions of loss of heterozygosity overlap in 15 RCCs. Results suggested that most RCCs exhibit loss in a region which brackets the t(3;8) familial chromosome translocation at 3p14.2, and some show additional deletions within the U2020 small cell lung carcinoma deletion at 3p12.