Water skiing is associated with severe injuries to the proximal hamstring muscles. We wanted to define the mechanism of injury, describe the associated pathologic changes, determine the functional limitations of patients, and suggest measures to prevent injury. Twelve patients with water skiing-related hamstring injuries were included. Six patients were experienced skiers and six were novices. The mechanism of injury was identical in five of six novice skiers. Each sustained the injury while attempting to get up on one or two skis from a submerged position. In contrast, the expert skiers all sustained injury secondary to a fall while skiing. Physical examination documented evidence of complete or partial avulsion of the proximal hamstring muscle origins in all patients. In addition, six patients had magnetic resonance imaging or computed tomography scans that confirmed the location and extent of the tear. Convalescence ranged from 3 months to 1.5 years before the patient could return to vigorous activities. Seven patients (58%) returned to most of their preinjury sports, albeit at a lower level. Five patients (42%), all with complete disruptions, were unable to run or participate in sports requiring agility. Two of these patients required delayed surgical repairs because of persistent functional limitations.