In this pilot, case-controlled investigation of 43 colorectal and 41 control male patients, we compared associations of colorectal cancer with the aromatic amine acetyltransferase polymorphism, nutritional and demographic characteristics, medical histories, industrial and occupational histories, and exposures from home environments and personal habits. Persons with the "fast" acetylator trait were at greater risk of colorectal cancer (odds ratio: 2.48; 95% confidence interval: 1.02, 6.03). Results that differed from previous reports were positive associations of colorectal cancer with agricultural and manufacturing industries and with consumption of meats prepared by smoking, curing, and barbecueing. As expected, exercise frequency, cruciferous vegetables, and dietary fiber served as protective factors.