Objectives: To investigate the influence that match exposure has upon injury risk in Rugby Union. Method: A seven-season (2006/7 2012/13) prospective cohort study of time-loss injuries in 1253 English Premiership professional players was conducted. Players’ 12-month match exposure (number of matches a player was involved in for ≥20 mins in the preceding 12 months) and 1-month match exposure (number of full-game equivalent [FGE] matches in preceding 30 days) were assessed as risk factors for injury using a nested frailty model and magnitude-based inferences. Results: Twelve-month match exposure was associated with injury risk in a non linear fashion, with players who had been involved in less than ≈15 or greater than ≈35 matches over the preceding 12-month period being more susceptible to injury. Monthly match exposure was linearly associated with injury risk (hazard ratio [HR]: 1.14 per 2-SD [3.2 FGE] increase, 90% CI: 1.08 1.20; likely harmful), although this effect was substantially attenuated for players in the upper quartile for 12-month match exposures (>28 matches).Conclusion: A player’s accumulated (12-month) and recent (1-month) match exposure substantially influences their current injury risk. Careful attention should be paid to planning the workloads and monitoring the responses of players involved in a: 1) high (>≈35) number of matches in the previous year; 2) low (<≈15) number of matches in the previous year; 3) low-moderate number of matches in previous year but who have played intensively in the recent past. These findings make a major contribution to evidence-based policy decisions regarding match workload limits in professional Rugby Union.