The purpose of our study was to detect somatic changes in renal cell carcinoma by multilocus fingerprinting. DNA fingerprints were generated from the DNA of normal and malignant renal tissue samples of 29 patients with nonhereditary kidney carcinoma by using oligonucleotide probes specific for simple repeat motifs such as (GTG)5, (CA)8, (GACA)4, or (TTAGGG)3. Each probe rendered a typical fingerprint pattern, because it is specific with respect to the target regions recognized in the genome. The restriction enzymes used were HinfI and HaeIII. Changed banding patterns were detected by using (GTG)5 in 20% of the tumors, in 20% for (CA)8 after HinfI digestion, and in 10% after HaeIII digestion. Even more informative probes were (GACA)4, showing 70% changes after HaeIII digestion, and (TTAGGG)3, with 80% changes after digestion with either enzyme. Since the simple repeat motifs recognized by (GACA)4 are localized on the short arms of the acrocentric chromosomes (13, 14, 15, 21, and 22), it is possible that sequences important for renal carcinogenesis are present in these regions. The observation of changes in regions to which (TTAGGG)3 hybridizes points to an involvement of DNA elements in telomeric sequence related regions in human kidney tumor formation.