The objective was to determine the tuberculosis incidence and related factors among drug users in 3 methadone maintenance programmes in Amsterdam to see whether the present screening procedures are adequate. The study population was selected from the Central Methadone Register (CMR). Cases were identified during hospitalization and during routine screening of ambulatory methadone clients. The data were generated by the drug and tuberculosis departments of the Amsterdam Municipal Health Service (MHS). From 5,044 clients, 43 new cases were identified. The incidence of tuberculosis was 386 per 100,000 person years (py) and increased with age and period of registration with the CMR. After correction for age, sex and period of registration, the incidence among clients of general practitioners (GP) was the lowest. The incidence among the general MHS clients is 9 times this and in the MHS programme for prostitutes and illegal foreigners 27 times higher than in the GP population. The increased risk for drug users treated at the MHS indicates lifestyle as a risk factor; MHS clients are more involved in the drugscene than GP clients. On the basis of this study, periodic screening limited to clients of the MHS would seem to be adequate for the present.