Background: Effective, accessible biopsychosocial treatments are needed to manage chronic knee pain on a population level. Objective: To evaluate the effectiveness of Internet-delivered, physiotherapist-prescribed home exercise and pain-coping skills training (PCST). Design: Pragmatic parallel-group randomized, controlled trial. (Australian New Zealand Clinical Trials Registry: ACTRN12614000243617) Setting: Community (Australia). Patients: 148 persons aged 50 years or older with chronic knee pain. Intervention: The intervention was delivered via the Internet and included educational material, 7 videoconferencing (Skype [Microsoft]) sessions with a physiotherapist for home exercise, and a PCST program over 3 months. The control was Internetbased educational material. Measurements: Primary outcomes were pain during walking (11-point numerical rating scale) and physical function (Western Ontario and McMaster Universities Osteoarthritis Index) at 3 months. Secondary outcomes were knee pain, quality of life, global change (overall, pain, and functional status), arthritis selfefficacy, coping, and pain catastrophizing. Outcomes were also measured at 9 months. Results: Of participants enrolled, 139 (94%) completed primary outcome measures at 3 months and 133 (90%) completed secondary outcome measures at 9 months; multiple imputation was used for missing data. The intervention group reported significantly more improvement in pain (mean difference, 1.6 units [95% CI, 0.9 to 2.3 units]) and physical function (mean difference, 9.3 units [CI, 5.9 to 12.7 units]) than the control group at 3 months, and improvements were sustained at 9 months (mean differences, 1.1 units [CI, 0.4 to 1.8 units] and 7.0 units [CI, 3.4 to 10.5 units], respectively). Intervention participants showed significantly more improvement in most secondary outcomes than control participants. At both time points, significantly more intervention participants reported global improvements. Limitation: Participants were unblinded. Conclusion: For persons with chronic knee pain, Internetdelivered, physiotherapist-prescribed exercise and PCST provide clinically meaningful improvements in pain and function that are sustained for at least 6 months.