OBJECTIVE: To assess the prevalence of symptomatic knee, hand, and hip osteoarthritis (OA) in the general adult population of Greece. METHODS: This cross-sectional population based study was conducted on the total adult population of 7 communities (8547 subjects) and on 2100 out of 5686 randomly selected subjects in an additional 2 communities. Sixteen rheumatologists visited the target population at their homes; an interview based on a standardized questionnaire was conducted and clinical evaluation and laboratory investigations were done, when necessary. ACR classification criteria were used for diagnosing symptomatic OA. RESULTS: Of the final target population of 10,647 subjects, 8740 (82.1%) participated in the study. The age and sex adjusted prevalence of symptomatic knee, hand, and hip OA was 6.0% (95% CI 5.6-6.4), 2% (1.8-2.2), and 0.9% (0.7-1.1), respectively. Symptomatic knee, hand, and hip OA prevalence was significantly higher among women than men and increased significantly with age. Symptomatic knee OA was significantly more common in the rural compared to urban and suburban populations. Logistic regression analysis showed a significant association of female sex and age > or = 50 years with all sites of OA, of obesity with knee and hip OA, and of a low level of education with knee OA. CONCLUSION: Symptomatic knee, hand, and hip OA is common in the general adult population of Greece, showing a female preponderance and a prevalence increasing with age. Female sex and age are risk factors for all sites of OA, obesity for knee and hip OA, and a low level of education for knee OA.