Background: Recent systematic reviews and international guidelines recommend patient education, exercises, and weight control (if overweight) as first-line treatment for patients with hip or knee osteoarthritis (OA). The Active with osteoArthritis (AktivA) program is a physiotherapy model for the implementation of these guidelines into clinical primary care practice. The purpose of the present study was to evaluate the long-term effects of and adherence to the AktivA program for patients with mild to moderate knee or hip OA. Methods: The AktivA program includes three modules: a physiotherapy certification course, a patient education and exercise program and an electronic quality register. An electronic questionnaire including questions about, pain, quality of life, physical activity, self-efficacy and satisfaction with the AktivA program are sent to the participants at inclusion and after 3, 12 and 24 months. A linear mixed model for repeated measurements was used to assess the difference between the follow-up times. Results: Until January 2020, 6245 patients were included in the register. The response rates were 98%, 86% and 63% at 3, 12 and 24 months, respectively. After participating in the AktivA program, the patients reported decreased pain and increased health-related and disease-specific quality of life at three months and the positive effect was maintained up to two years after inclusion. The proportion of patients reporting to be inactive or having a low physical activity level was reduced from 43% to 22%. After two years, more than 80% of the participants reported to use what they have learned from the AktivA program at least once a week. Conclusions: Two years after inclusion in the AktivA physiotherapy program, the patients still report reduced pain, increased quality of life and higher activity levels.