There is a lack of epidemiological research in adolescent Gaelic games, with previous research primarily focusing on elite adult males. This study aimed to prospectively capture the epidemiology of injury in male adolescent Gaelic games over one year. Prospective cohort study. Two hundred and ninety two (15.7±0.8 years) male adolescent Gaelic footballers and hurlers took part in a one year prospective epidemiological study. Injuries were assessed weekly by a certified Athletic Rehabilitation Therapist and an injury was defined as any injury sustained during training or competition resulting in restricted performance or time lost from play. An injury report form was utilised to standardise injury information. Match injuries were more frequent in Gaelic footballers (9.26 per 1000h) and hurlers (11.11 per 1000h) than training injuries (2.69 and 3.01 per 1000h, respectively). Over a quarter of injuries in adolescent Gaelic footballers (26.7%) and hurlers (26.5%) were overuse in nature. Recurrent injuries were also frequent, particularly in adolescent Gaelic footballers (47.3%). Lower limb injuries predominated (football 74.7%, hurling 58%), particularly in the knee (18.7%, 20.0%) and ankle (12.0%, 10.0%). Hamstring injuries were more frequent in footballers (13.3%), with lower back injuries more common in hurlers (22.0%). Minor injuries were common in hurling (61.7%), with moderate (20.8%) and severe (37.5%) injuries predominant in Gaelic football. Injuries are frequent in adolescent Gaelic games and this study sets the scene for the establishment of injury prevention strategies for this at risk population.