Aims: To define the prevalence of hypertension, a major cause of morbidity and mortality in blacks, and related biosocial factors in an urban African population group. Methods: The setting was that of a civil service population in Ibadan, a major city in Southwestern Nigeria. Nine hundred and ninety-eight civil servants selected by multistage sampling participated in the survey. Biosocial data including smoking history, alcohol use and level of physical activity; anthropometry, blood pressure and plasma glucose measurements were obtained. Diagnosis of hypertension was based on blood pressure of у160/95 mm Hg or known hypertensive on treatment. Results: The overall prevalence rate of hypertension was 10.3% (CI, 8.4%, 12.2%), rates of 13.9% and 5.3% were obtained in men and women respectively in spite of a much higher rate of generalised obesity in the latter. Hypertension was associated with higher salary grade level, but there was no relationship found with regular exercise, smoking and alcohol. Obesity (body mass index (BMI) у30 kg/m 2 ) was associated with hypertension only in women. A two-sided t-test demonstrated