This study investigated the incidence, site, nature and causes of injuries sustained in the New Zealand national rugby league sevens tournament. A total of 218 players competing in 47 matches were studied. All injuries sustained within the tournament were prospectively recorded. Injuries were categorised according to the severity assessment at the time of the injury. Information obtained included the time, site, nature and cause of the injury. The incidence of injury was 497.6 per 1000 playing hours. More than 40% (216.1 per 1000) of injuries sustained occurred within the lower limbs. The shoulder was the single most commonly injured site (78.6 per 1000). Sprains were the most common injury type (189.9 per 1000). The ball-carrier sustained significantly more (p<0.05) injuries than the tackling player (216.1 per 1000 [43.4%] versus 117.8 per 1000 [23.7%]). There were significantly more injuries on the first day of competition than on the second day of competition (600.4 per 1000 [76.3%] versus 320.9 per 1000 [23.7%]). The findings of higher injury rates on the first day of competition and during the second period of matches suggest that playing intensity and player fatigue may contribute to injuries in rugby league sevens.