Patient non-compliance is regarded as a major cause of treatment failure in tuberculosis. In view of the rising tuberculosis incidence rate in the western Cape it was decided to determine which factors were related to treatment compliance. Information about patients on treatment for tuberculosis was obtained from 75% of the 68 local authorities surveyed (representing 90% of the surveyed population). Patients who had received greater than or equal to 75% of their expected doses by the survey date were considered compliant. Overall compliance was 82.5%. The lowest rates were reported in teenagers, children under 5 years, blacks and unemployed patients. The results have implications for tuberculosis control strategies.