Background: Provision of antiretroviral therapy has expanded in Sub-Saharan Africa and quality assurance of antiretrovirals is of crucial importance for the success of treatment programmes. Therefore WHO, in co-operation with national authorities, organized a quality survey of antiretrovirals in selected African countries. Methods: The survey was performed in Cameroon, the Democratic Republic of Congo, Kenya, Nigeria, United Republic of Tanzania, Uganda and Zambia. Country teams made up of WHO country officers and national authority representatives collected samples at public and private sector antiretroviral procurement organizations and treatment centres around the capital cities. Samples included monocomponent products of didanosine, efavirenz, lamivudine, nevirapine, stavudine and zidovudine, and fixed-dose combinations of lamivudine/zidovudine, stavudine/lamivudine, stavudine/lamivudine/nevirapine. All samples were tested by the Official Medicines Control Laboratory of Switzerland, Swissmedic, for appearance, labelling, identity, related substances, and content of each active ingredient. In addition, capsules and tablets were tested for uniformity of mass and either dissolution or disintegration; oral solutions were tested for pH if appropriate. Methods of the International Pharmacopoeia, United States Pharmacopoeia, Indian Pharmacopoeia or manufacturers’ methods with method transfer were used as appropriate. Sampling and testing were carried out over a period of six months from 13 June to 15 December 2005. Findings: None of the antiretrovirals sampled had any critical quality deficiencies which would pose a serious risk to patients. In 394 samples collected, the overall failure rate was 1.8%. One sample contained a broken tablet and tablets with chipped coating. Two samples were insufficiently labelled on the immediate packaging. The content of active ingredient of one sample exceeded the upper limit. One of 163 samples tested for disintegration failed to disintegrate completely within 30 minutes, and two of 153 samples tested for dissolution showed lower results than required. Fifty-three percent of sampled products were WHO-prequalified. Information on registration by National Drug Regulatory Authorities was available for 285 products; of these, 84% were registered. Products not registered at the time of sampling were found in three countries, mostly at private sector facilities, and constituted 12% of the total of 394 sampled products. Conclusions: The generally good quality and safety of products sampled indicate the positive effect of common efforts of National Drug Regulatory Authorities, WHO and other organizations involved in prequalification and purchase policies. Market control was still incomplete in at least three countries. Since the survey was limited to official distribution points and treatment centres around the capital cities, these results cannot be generalized to the entire territories of the countries surveyed.