BACKGROUND: Knee bursitis (KB) is a common disorder in specific occupations requiring frequent and/or sustained kneeling postures.AIMS: To assess the prevalence of KB in the general working population. METHODS: Between 2002 and 2005, a total of 3710 workers of a French region were randomly included in the study. A standardized physical examination of the knee was performed when knee pain was reported by the worker during the preceding 12 months. The criteria for diagnosis of KB were (i) the presence of pain and/or tenderness in the anterior face of the knee at the date of the examination (or for at least 4 days in the preceding week) and (ii) the presence of swelling and/or pressure-induced pain of the pre- or infra-patellar bursa. Occupational risk factors were assessed by a self-administered questionnaire. RESULTS: The prevalence of uni- or bilateral cases of knee bursitis was low: 0.6% [0.2-0.9] in men and 0.2% [0.0-0.6] in women. The highest prevalence was observed in the construction sector (2.3% [0.8-5.4]) and in the food and meat processing industries (1.4% [0.4-3.5)]. More blue-collar workers were affected than other occupation categories (0.8% [0.3-1.2] versus 0.1% [0.0-0.4]). CONCLUSIONS: The study showed a concentration of cases among male workers exposed to heavy workloads and frequent kneeling.