Objectives: To determine head impact characteristics for amateur rugby union players. Design: Descriptive cohort study. Methods: A total of 20,687 head impacts greater than 10g over a 2013 amateur senior rugby union season of matches for one team of 38 players. Analyses by matches home/away, won/lost and first/second season halves. Additional analyses by player position and head impact position. Results: There were more significantly impacts for matches played away (124 ± 218), matches won (111 ±178) and matches in the first half of the competition season (147 ± 220). Front-row forwards (FRF) recorded more impacts to the head at away games (RR: 1.5 [95% CI: 1.5-1.6]; p<0.0001) compared with home games. The front of the head recorded a longer impact duration (t(2158)=11.2; p<0.0001; d=0.38), and had a higher resultant PLAg (χ2(1)=86.6; p<0.0001; z=-9.7; p<0.0001; d=0.20), PRA(rad/s2) (χ2(1)=62.4; p<0.0001; z=-8.4; p<0.0001; d=0.80) and RWECP (χ2(1)=60.3; p<0.0001; z=-7.6; p<0.0001; d=0.09) in games won when compared with games lost. Conclusion: The nature of matches affected head impacts measured by an instrumented mouthguard in amateur rugby union players with more frequent and greater magnitude impacts for away, won and first half season of matches. The finding that there were far more impacts experienced by players during the first half of the season compared to the second half of the season could be related to the players level of fitness level. There were more impacts recorded to the side of the head in matches won and the first half of the season.