Abstract A retrospective cohort study was conducted in Thailand from 2007 to 2009 to evaluate the efficacy of a safety riding program in preventing motorcycle-related injuries. A training group of motorcyclists were certified by the Asia-Pacific Honda Safety Riding Program in either 30-h instruction (teaching skills, riding demonstration) or 15-h license (knowledge, skills, and hazard perception) courses. The control group consisted of untrained motorcyclists matched on an approximately 1:1 ratio with the training group by region and date of licensure. In total, there were 3250 subjects in the training group and 2963 in the control group. Demographic data and factors associated with motorcycle-related injuries were collected. Motorcycle-related injuries were identified using the Road Injuries Victims Protection for injuries claims and inpatient diagnosis-related group datasets from the National Health Security Office. The capture–recapture technique was used to estimate the prevalence of injuries. Multivariate analysis was used to identify factors related to motorcycle-related injuries. The prevalence of motorcycle-related injuries was estimated to be 586 out of 6213 riders (9.4%) with a 95% confidence interval (CI): 460–790. The license course and the instruction course were significantly associated with a 30% and 29% reduction of motorcycle-related injuries, respectively (relative risk 0.70, 95% CI: 0.53–0.92 and 0.71, 95% CI: 0.42–1.18, respectively). Other factors associated with the injuries were male gender and young age. Safety riding training was effective in reducing injuries. These training programs differ from those in other developed countries but display comparable effects. Hazard perception skills might be a key for success. This strategy should be expanded to a national scale.