We conducted a study to evaluate tuberculosis (TB) risk in Japan by work performed, either paid or unpaid. We collated information on sex, age, employment category, occupation, and family history from 1120 registration cards of new TB cases at two wards in Nagoya City over seven years (1989-1995). We used census data and data from the Survey of Physicians, Dentists and Pharmacists conducted in 1990 to estimate the population at risk by employment category and occupation. Elevated TB incidence rates were observed for female nurses (SIR: 3.81; 95% CI: 1.97-6.65), clinical laboratory technicians (SIR: 25.00; 6.81-63.99), and males without a paid job (SIR: 1.35; 1.20-1.53). A work environment conducive to transmission may have increased the TB risk in female nurses and clinical laboratory technicians. Male jobless people and institutionalized elderly residents may have enhanced the TB risk for males without a paid job.