A first-degree relative with pancreatic cancer is found in 5% to 10% of patients with pancreatic carcinomas, suggesting an inherited predisposition for this neoplasm. The recently identified DPC4 tumor suppressor gene is a strong candidate for the gene responsible for the familial form of pancreatic carcinoma. DPC4 was identified in a consensus area of homozygous deletion in pancreatic carcinomas, and it is biallelically inactivated in approximately 50% of sporadic pancreatic carcinomas. The coding sequence of this gene is 1660 nucleotides in length, covering 11 exons. We describe optimized primers and conditions used in polymerase chain reaction and cycle sequencing of the entire DPC4 coding sequence of 25 individuals (eight with pancreatic carcinoma) from 11 kindreds with a familial aggregation of pancreatic carcinoma. No mutations in the coding sequences of the DPC4 gene were found; hence, it appears that germline mutations in DPC4 cannot account for many of the familial aggregations of pancreatic carcinoma.