Measles remains a major cause of child and infant mortality in Africa. Burkina Faso was the first country in Africa to run mass measles vaccination campaigns. The "Commando" vaccination program in 1984 immunized children aged between 9 months and 6 years old. The EPI was then implemented across the whole country; and with particular emphasis on the North Central region (with the help of two Non Governmental Organizations). Coverage cluster surveys were conducted in 1987 and 1989. In addition, a community-based evaluation of the immunization program and a serological survey were run in January 1989. A measles epidemic started in March 1989 in the Eastern province (Namentenga) of the North Central region and lasted until the rainy season. A survey reported 230 cases of which a large proportion were adults. Vaccine efficacy (85%) was normal. Index cases were from a neighbouring province. Epidemiological and serological surveys in 1989 indicated that the circulation of the wild type virus had been low since the 1984 "Commando" vaccination program. The epidemic was due to unsatisfactory vaccinal coverage (53%) which had further declined (35%). Consequently the primary health care system is being mobilized to improve vaccinal coverage.