The purpose of this transverse prospective study was to assess risk factors associated with osteoarthritis (OA) of the knee observed in a rheumatology outpatient clinic in Ouagadougou, Burkina Faso. All patients presenting osteoarthritis of the knee diagnosed according to the clinical and radiological criteria of the American College of Rheumatology (ACR) were recruited over a 9-month period from November 2006 to July 2007. A total of 118 patients including 108 women were studied. Mean patient age was 55.7 +/- 10.8 years. Pain and disability scores assessed using theLequesne index were greater than 8 in 87.3% of patients. Hydarthrosis was observed in 56.5% of patients. The most common associated risk factors for development of osteoarthritis of the knee were obesity (42.4%), menopause in women (66.7%), history of OA (43.2%), and previous knee injury (19.5%). The most common associated risk factors for progression of osteoarthritis of the knee were Heberden nodes (19.5%) and genu varum (52.5%). The risk factors for development and progression of osteoarthritis of the knee in the subsahalian population of Ouagadougou are the same as in the Caucasian population of industrialized countries. An unexpected finding in this black African population was the high prevalence of Heberden nodes.