Background: In spite of effective therapy, tuberculosis (TB) is still a major health problem in developing countries. In 1993, therefore, the World Health Organization declared TB a global emergency. In South Africa, TB is one of the most prevalent diseases, with an incidence of 556 per 100 000 population. In spite of free TB drugs in the public service and the directly observed treatment short course (DOTS) strategies, there is still a high prevalence of TB and a high treatment interruption rate in rural South Africa. Methods: The objectives of this study were to establish the prevalence of TB and reasons for the interruption of TB treatment by patients attending Mbekweni Health Centre in King Sabata Dalidyebo (KSD) district in the Eastern Cape province. This was a crosssectional study in which data were collected from 15 July 2004 to 15 January 2005 from patients who were on TB treatment and interrupted their treatment between 6 August 2001 and 30 December 2003. Results: Of the 255 TB patients who attended for treatment, 121 (47.5%) had interrupted their treatment. Reasons given for interruption included change of living place (18.96%), no money to go to the clinic (15.52%), feeling better (13.78%), side effects of the drug (6.90%), did not know the treatment course (5.17%), physical disability either old or too sick to collect treatment and nobody to help (5.17%), clinic too far (1.73%), drug not available in the clinic (13.83%) and no reasons (8.62%). Conclusion: The prevalence of treatment interruption was high in this study. Change of living place, lack of money for visiting the clinic to collect treatment, feeling better, and no drugs at the clinic were the major reasons given for interruption of treatment. Ensuring the availability of TB drugs at the health centre/clinic, patient education about TB and strengthening the DOTS programme, including a stipend for the DOTS supervisors, would help to reduce the prevalence of treatment interruption. This article has been peer reviewed. Full text available at www.safpj.co.za SA Fam Pract 2008;50(6):47