Most studies of smoking and pancreatic cancer have used male subjects or combined men and women together in statistical analyses. There is little information on the relative risk of smoking and pancreatic cancer in women. Because of the high case-fatality rate, many of these studies were also based on information gathered from proxy respondents, in which smoking habits may not be recalled with certainty. A hospital-based study of 484 male and female patients with pancreatic cancer and 954 control subjects was conducted based on direct interviews of incident cases. Compared to never smokers, the odds ratio (OR) for current cigarette smokers was 1.6 [95% confidence interval (CI), 1.1-2.4] for men and 2.3 (95% CI, 1.4-3.5) for women. In women, but not in men, there was a trend in the ORs with years of daily cigarette consumption (P < 0.01). Filter cigarettes offered no protective advantage compared to nonfilter cigarettes. Among men, the OR was 2.1 (95% CI, 1.2-3.8) for pipe/ cigar smokers and 3.6 (95% CI, 1.0-12.8) for tobacco chewers. Tobacco smoke causes pancreatic cancer when inhaled into the lungs. Tobacco juice may also cause pancreatic cancer when ingested or absorbed through the oral cavity. These data suggest that smoking is a cause of pancreatic cancer in women and that the risks for female smokers are comparable to male smokers. Nevertheless, the causes of most pancreatic cancers are unknown.