The authors conducted a case-control study on the relationship between socioeconomic factors and tuberculosis in the former coalmining area of Chikuho where tuberculosis incidence was high. The cases were 292 newly registered tuberculosis patients in Iizuka Health Center District, in the former coalmining area of Chikuho. Controls were randomly selected from resident cards, matched for sex, age, and place of residence. The results of comparing the cases with the controls were as follows: 1) Significantly more of the male cases had had long-term employment in coalmining. Exposure to dust is likely to be associated with the high tuberculosis incidence in males aged 50 or over. 2) The cases showed significantly higher unemployment levels and lower educational levels. Among females, more of the cases were unmarried or divorced, and a significantly higher proportion were receiving welfare benefits. The high incidence of tuberculosis is probably related to a low socioeconomic level resulting from closure of coalmines. 3) No difference was observed in working hours, night shifts, smoking rate, and drinking habits. These factors are unlikely to be singly related to the onset of tuberculosis.