The influence of immigration from six selected Asian countries--Japan, Korea, Philippines, India, China and Hong Kong--on the incidence of tuberculosis in British Columbia has been examined. During the period 1982-1985 the average annual incidence of bacillary tuberculosis in these immigrants was more than six times as great as the overall British Columbia rate and contributed a quarter of the cases of active bacillary tuberculosis in this province whereas the immigrants from these countries represented only 3.7% of the total population. The clinical patterns of active tuberculosis by birthplace were analysed. A high proportion of cases of lymphadenitis was seen among all immigrants from Asia, particularly those from the Philippines. Both primary and secondary drug resistance was substantially higher than in Canadian-born patients. The frequency of primary drug resistance was higher among patients aged less than 40 years than those aged 40 or more.