Drug resistance surveillance conducted by the National Tuberculosis and Leprosy Control Programme (NTLP) Uganda from 1996-1997 in collaboration with the Armauer Hansen Institute/German Leprosy Relief Association (GLRA), Germany, for the WHO/IUATLD Global Project on Anti-Tuberculosis Drug Resistance Surveillance. To determine the prevalence of primary and acquired anti-tuberculosis drug resistance in Uganda. The survey area covered three GLRA-supported operational NTLP zones, corresponding to 50% of the Ugandan population. A representative random sampling of individual patients was chosen as sampling procedure. Altogether 586 smear-positive TB patients (537 new cases and 49 previously treated cases) were included in the survey. For primary resistance the results were as follows: isoniazid (H) 6.7%, rifampicin (R) 0.8%, ethambutol (E) 6.1%, streptomycin (S) 13.4%, thioacetazone (T) 3.2%, pyrazinamide (Z) 0%, multidrug resistance (MDR) 0.5%; for acquired resistance they were: H 37.8%, R 4.4%, S 22.2%, E 11.1%, T 20.0%, Z 0%, and MDR 4.4%. According to these data the NTLP Uganda has been effective in preventing high levels of primary drug resistance. If it is assumed that the sampling process reflects the distribution of new patients and previously treated patients in the study areas, the amount of acquired resistance (any resistance) in the community of smear-positive patients is approximately 5%. To further monitor programme performance the NTLP will embark on a nationwide survey in 1998/1999.