ObjectivesIdentify tackle characteristics associated with concussions in male professional rugby league. DesignCase–control study. MethodsTackles resulting in 196 clinically diagnosed concussions and 6592 non-concussive tackles were analysed, from the men's rugby league Super League between 2018 and 2022. Eleven tackle characteristics were coded for each tackle, and Firth penalised logistic regression models were employed to identify influential variables through forward stepwise selection. Three multivariate models were produced; all (i.e., ball-carrier and tackler), tackler, and ball-carrier concussions. ResultsOf the 196 concussions, 70 % occurred to the tackler and 30 % to the ball-carrier. Initial impact location on the ball-carrier was identified as a predictor in all models, specifically the shorts, upper- and lower-leg (OR 9.1–12.3, compared to shoulder) for tacklers and head/neck (OR 66.1, compared to shoulder) for ball-carriers. Tackler head placement in front of the ball-carrier (OR 8.5, compared to away from the body) and a ball-carrier leading arm in any position (OR 4.8–22.1, compared to no leading arm) provided the greatest odds of a tackler concussion. For player's body position the greatest risk of concussion for all players was observed when both players were falling/diving (OR 8.8, compared to both players upright). One (OR 4.9, compared to two) and four (OR 3.7, compared to two) defender tackles provide the greatest odds for all concussions. ConclusionsConcussion prevention strategies should aim to reduce head impacts by deterring initial contact with the ball-carrier's head/neck. Tackle technique should prioritise making initial impact with the torso and avoid the head being in front of the ball-carrier and any leading arms.