Background.The Thinking Healthy Programme (THP) is an evidence-based psychological intervention endorsed by the World Health Organization, tailored for non-specialist health workers in low- and middle-income countries. However, training and supervision of large numbers of health workers is a major challenge for the scale-up of THP. We developed a ‘Technology-Assisted Cascaded Training and Supervision system’ (TACTS) for THP consisting of a training application and cascaded supervision delivered from a distance.Methods.A single-blind, non-inferiority, randomized controlled trial was conducted in District Swat, a post-conflict area of North Pakistan. Eighty community health workers (called Lady Health Workers or LHWs) were randomly assigned to either TACTS or conventional face-to-face training and supervision by a specialist. Competence of LHWs in delivering THP post-training was assessed by independent observers rating a therapeutic session using a standardized measure, the ‘Enhancing Assessment of Common Therapeutic factors’ (ENACT), immediately post-training and after 3 months. ENACT uses a Likert scale to score an observed interaction on 18 dimensions, with a total score of 54, and a higher score indicating greater competence.Results.Results indicated no significant differences between health workers trained using TACTS and supervised from distancev.those trained and supervised by a specialist face-to-face (mean ENACT score M = 24.97,s.d. = 5.95v.M = 27.27,s.d. = 5.60,p = 0.079, 95% CI 4.87–0.27) and at 3 months follow-up assessment (M = 44.48,s.d. = 3.97v.M = 43.63,s.d. = 6.34,p = 0.53, CI −1.88 to 3.59).Conclusions.TACTS can provide a promising tool for training and supervision of front-line workers in areas where there is a shortage of specialist trainers and supervisors.