Study Objective:To ascertain the nature and extent of motorboat propeller injuries in Wisconsin.DesignRetrospective study of deaths and injuries from outboard motor propellers reported to the Wisconsin Division of Health, Vital Statistics, and reported by a statewide retrospective survey of emergency departments.ResultsFor the study period 1987 through 1989, three fatalities were found in Vital Statistics and Emergency Department records and 14 nonfatal injuries reported by respondents to the Wisconsin emergency department survey. Thirty-six percent (5 of 14) of the nonfatal injuries occurred in water skiers. Injuries involved the lower extremities in 10 of 14 nonfatal cases (71%), frequently in association with other anatomic areas. At least three cases involved very severe injuries, with mean acute care medical charges of more than $100,000 per case.ConclusionsWhere boating is common, fatal and severe injuries from propellers occur with regularity. These injuries are often severe, requiring complicated and expensive treatment. The authors urge improved documentation of the incidence of propeller injuries, and an active exploration of prevention strategies including fitting motorboat propellers with guards.