A case-control study was conducted to investigate occupational risk factors for upper respiratory and digestive tract cancers (nose, lips, buccal cavity, pharynx, and larynx) in the north of France. Two hundred and eighty three cases of histologically confirmed cancer in men treated during the first semester of 1983 at the Regional Cancer Institute were included in the study. Two controls per case were chosen from patients in the medical wards of the local general hospitals in the same geographical area as the case, who did not have cancer. Controls were individually matched for sex, age (+/- 18 months), ethnic group, area of residence, and smoking and alcohol drinking history. All subjects were questioned about occupations in which they had worked for at least 15 years. Odds ratios for major occupational categories were estimated using conditional logistic regression for matched samples. Significant associations were found between wood work and nasal cancer (four cases, no control) and farming and lip cancer (odds ratio 5.3, 95% confidence interval 1.1-26.8). Pharyngeal cancer was associated with the textile industry (OR 2.4, 95% CI 1.0-5.7) and the building industry (OR 2.0, 95% CI 1.1-3.9). Coal miners showed a threefold excess risk for cancer of the lip (4 cases, no control), buccal cavity (OR 3.5, 95% CI 1.1-11.8), and larynx (OR 3.2, 95% CI 1.1-9.7).