We conducted a prospective cohort study from 1993 to 1997 to determine the frequency and severity of injury in men's Canada West university football. The Canadian Intercollegiate Sport Injury Registry was used to document baseline preseason data, daily athlete participation, and subsequent injury from five varsity football teams. An injury was defined as "any injury resulting in one or more complete or partial sessions of time loss" or "any concussion or transient neck neurologic injury." The annual proportion of injured athletes ranged from 53.5% to 60.4%, with a 5-year total of 1,811 injuries. Regression analysis indicated that the rate of nonconcussion, nonneck neurologic injuries increased. Concussion (N = 110), hamstring strain (N = 88), and brachial plexus (N = 84) injuries were the most common, specific injury diagnoses. Knee injuries resulted in the highest rate of severe (greater than or equal to 7 sessions of time loss) injury and resulted in the most time loss (3,350.5 sessions). Ligament sprains and muscle strains and spasms accounted for approximately half of all injury diagnoses. A total of 1,173 injuries (65%) were related to contact between players or between players and other obstacles. Future studies should be conducted to identify risk factors for the ultimate purpose of implementing injury prevention strategies.