Background Treating knee osteoarthritis (OA) in the medical phase is today well standardized. Guideline orientated approaches aiming at increasing physical activity (PA), improving pain and disability. Objectives To assess effectiveness of self-management exercise program associated to spa therapy at 3 month on the improvement of physical activity (PA) level, disability, pain, anxiety, fears and believes in symptomatic knee osteoarthritis people. Methods Prospective, multicentric, quasi-randomized controlled trial with alternate month design method (one month periods). People with symptomatic knee OA people (stage I-IV, Kelgren and Lawrence scale) with low and moderate PA level were included in 3 spa therapy resorts. Intervention group (IG) received 5 self-management exercise sessions (1h30; education, aerobic, strength training, range of motion) + information booklet + 18 sessions (1h) of conventional spa therapy (STC). Control group (CG) received information booklet + 18 sessions of STC. The primary outcome was changes at 3 months in PA level (IPAQ short form score) and secondary outcomes were WOMAC function, pain (VAS), HAD anxiety/depression, KOFBeQ fears and believes changes. Results 131 subjects were included. The mean age was 65.6 years [± 6.7]. WOMAC function score was 22.1/68 [±11.3] and pain was 4.6/10 [± 1.9] at inclusion. Both groups significantly increased PA level measured with continuous IPAQ total score (MET-minutes/weeks), with superiority for IG (+77.8%; p=0.0062) than CG (+50.7%; p=0.0099). There was no change in setting time. Disability (-11.3%; p=0.0370) and pain (-15.2%; p=0.0032) also decreased significantly for both groups. Anxiety (-11.6%; p=0.0195) and fears and believes (-18.2%; p=0.0146) decreased significantly only in intervention group. Other data will be presented later