The relationship between family history of selected neoplasms in first-degree relatives and the risk of pancreatic, liver, and gallbladder cancer was investigated using data from a case-control study conducted in northern Italy on 320 histologically confirmed incident cases of liver cancer, 58 of gallbladder cancer, 362 of pancreatic cancer, and 1408 controls admitted to the hospital for acute, nonneoplastic, nondigestive tract disorders. Significant associations were observed between family history of hepatocellular carcinoma and primary liver cancer [relative risk (RR) = 2.4; 95% confidence interval (CI), 1.3 to 4.4], between family history of pancreatic cancer and pancreatic cancer (RR = 3.0; 95% CI, 1.4 to 6.6), and between family history of gallbladder cancer and gallbladder cancer (RR = 13.9; 95% CI, 1.2 to 163.9). The elevated risk of liver cancer associated with family history was not materially modified by adjustment for tobacco, alcohol, and personal history of cirrhosis and hepatitis (RR = 2.9; 95% CI, 1.5 to 5.3). Similarly, the risk for pancreatic cancer did not appreciably change after allowance for tobacco, alcohol, dietary factors, and medical history of diabetes and pancreatitis (RR = 2.8; 95% CI, 1.3 to 6.3). This pattern of risk would support the existence of a genetic component in the familial aggregation of liver and pancreatic cancer. In terms of population attributable risk, approximately 3% of the newly diagnosed liver and pancreatic cancers would be related to this familial component.