Irritable bowel syndrome (IBS) is a common disorder in the Western world. Its prevalence is yet to be fully determined in the African setting. This was a cross-sectional study of patients attending three General Outpatient clinics in Jos, Nigeria. Four hundred and eighteen randomly selected patients were interviewed using a structured questionnaire based on the Rome II diagnostic criteria for IBS. Excluded from the study were patients with established organic disease, memory problems, and pregnant women. Eighteen patients were excluded based on these criteria and 400 were analysed using Epi Info 2000 (Atlanta, Georgia, USA) statistical computer software. One hundred and thirty-two (33%) out of the 400 patients fulfilled the criteria for the diagnosis of IBS, the female to male ratio being 1.13 : 1. IBS was significantly associated with increasing age (P=0.03) and depression (P<0.001). The prevalence of IBS is high among patients attending primary care in the African setting with depression being the likely reason for seeking care.