Data on the prevalence of diabetes in Ghana is scanty and unreliable. In the present study we have ascertained the prevalence of diabetes, impaired fasting glycaemia (IFG) and impaired glucose tolerance (IGT) in a random cluster sample of Ghanaians aged 25 years and above from the Greater Accra area of Ghana. Diabetes, IFG and IGT were defined by criteria of the American Diabetes Association and World Health Organization. The mean age of the 4733 subjects involved in the study was 44.3+/-14.7 years, and participation rate was 75%. The crude prevalence of diabetes was 6.3%. Out of 300 subjects with diabetes, 209 (69.7%) had no prior history of the disease. Diabetes, IGT and combined IFG and IGT increased with age. The oldest age group (64+ years) had the highest diabetes prevalence (13.6%). The age-adjusted prevalence of diabetes, IFG and IGT, were 6.4, 6.0 and 10.7%, respectively. Diabetes was more common in males than females (7.7 vs. 5.5%) [P<0.05]. Worsening glycaemic status tended to be associated with increase in age, body mass index, systolic and diastolic blood pressures. Ascertainment of predictors for diabetes in Ghanaians and the significance of the relatively high rates of and IFG and IGT however, remain to be determined.