Background There is a risk of concussion when playing rugby union. Appropriate management of concussion includes compliance with the return-to-play regulations of the sports body for reducing the likelihood of premature return-to-play by injured players. Purpose To describe the proportion of rugby union players who comply with the sports body's regulations on returning to play postconcussion. Study design Prospective cohort study. Methods 1958 community rugby union players (aged 15-48 years) in Sydney (Australia) were recruited from schoolboy, grade and suburban competitions and followed over ≥1 playing seasons. Club doctors/physiotherapists/ coaches or trained injury recorders who attended the game reported players who sustained a concussion. Concussed players were followed up over a 3-month period and the dates when they returned to play (including either a game or training session) were recorded, as well as any return-to-play advice they received. Results 187 players sustained ≥1 concussion throughout the follow-up. The median number of days before players returned to play (competition game play or training) following concussion was 3 (range 1-84). Most players (78%) did not receive return-to-play advice postconcussion, and of those who received correct advice, all failed to comply with the 3-week stand-down regulation. Conclusions The paucity of return-to-play advice received by community rugby union players postconcussion and the high level of non-compliance with return-to-play regulations highlight the need for better dissemination and implementation of the return-to-play regulations and improved understanding of the underlying causes of why players do not adhere to return-toplay practices.