Abstract:The incidence of tuberculosis was investigated among 3,251 patients residing in Nagasaki city and diagnosed as schizophrenia between 1960 and 1978. Eighty‐two of the patients had tuberculosis. The expected number of schizophrenic patients with tuberculosis was calculated using the annual incidence rate of tuberculosis in the general population, and the difference between the observed number and the expected number was examined. The incidence rate of tuberculosis was significantly higher than that of the general population for both male and female schizophrenic patients. Similarly, the incidence rates of tuberculosis among schizophrenic patients born before 1925 and those born after that year were significantly higher than those of the corresponding age groups in the general population. In this paper we discuss these findings with reference to the literature on similar epidemiological studie