Objective. To compare the effectiveness of two educational courses aiming to improve adherence to recommendations in a Dutch physiotherapy practice guideline for hip and knee OA. Methods. Physiotherapists (PTs) from three regions in The Netherlands were invited to participate in a study comparing an interactive workshop (IW) with conventional education (CE). Participants were randomly assigned to one of the two courses. Satisfaction with the course (scale 0–10), knowledge (score range 0–76) and guideline adherence (score range 0–72) were measured at baseline, immediately after the educational course and 3 months after that. Data were analysed using a linear mixed model. Results. In total, 203 (10%) PTs participated in the IW ( n = 108) and the CE ( n = 95). There were no differences between groups at baseline. Satisfaction was significantly higher in the IW than in the CE group [mean scores (<scp>s.d.</scp>) 7.5 (1.1) and 6.7 (1.6), respectively ( P < 0.001)]. A significantly greater improvement in adherence was seen over time in the IW group compared with the CE group ( F = 3.763, P = 0.024), whereas the difference in improvement of knowledge was not significant ( F = 1.283, P = 0.278). Conclusion. An IW led to greater satisfaction and was more effective in improving adherence to recommendations in a PT guideline on hip and knee OA than CE, whereas the increase in knowledge did not differ significantly.