BACKGROUND:This study evaluated an intervention aiming to improve methadone maintenance therapy (MMT) service providers' interaction with their patients in China. METHODS:Sixty-eight MMT clinics were randomized to either an intervention or a control condition. Providers in the intervention group attended three group training sessions to enhance their communication skills. Trained providers were encouraged to practice the taught communication skills through provider-initiated individual sessions with their patients. A total of 418 service providers completed assessments from baseline to 24-month. Linear mixed-effects regression models were used to compare self-reported short-term and sustained improvement in provider-patient interaction between the intervention and the control conditions. RESULTS:The intervention group service providers perceived significantly greater short-term and sustained improvement in provider-patient interaction compared to the control group service providers (estimated difference (±SE): 1.20 (0.24) and 1.35 (0.33), respectively; p-values < 0.0001). Providers' baseline job satisfaction was significantly associated with a greater perceived improvement in provider-patient interaction for both periods (reg. coef. (±SE): 0.02 (0.01) and 0.04 (0.01) for short-term and sustained periods, respectively; p-values < 0.01). CONCLUSION:Study findings suggest that the intervention could be beneficial for improving perceived provider-patient interaction in MMT programs. Service providers' job satisfaction should be addressed in training programs for the improvement of provider-patient interaction.