AimTo record overuse injuries among male junior handball players throughout a handball season.DesignProspective cohort study.MethodsTen Norwegian junior male handball teams (145 players aged 16–18 years) were followed for one 10-month season. All players were sent the Oslo Sports Trauma Research Center Overuse Injury Questionaire every second week to record overuse injuries located in the shoulder, elbow, lower back and knee. The relative burden of overuse injuries was calculated in each anatomical area represented, defined as the proportion of the total cumulative severity score.ResultsThe average prevalence of all overuse injury problems was 39% (95% CI 29% to 49%) across all anatomical areas. The average prevalence of substantial overuse injury problems, defined as those leading to moderate or large reductions in training volume or sports performance, or to complete inability to participate, was 15% (95% CI 13% to 17%). Over the duration of the study, the cumulative incidence of overuse injury problems was 91% (133 players). Shoulder problems were the most prevalent (average prevalence 17%, 95% CI 16% to 19%), whereas knee problems had the greatest relative burden.ConclusionOveruse injuries, particularly in the shoulder and knee, have a substantial impact on junior handball players’ training participation and performance. Interventions to prevent overuse injuries among male junior handball players should focus on these areas.