Three hundred thirty chain saw injury patients arriving at the emergency clinic of a community hospital in the southeast United States between 1972 and 1979 were reviewed. Forty-eight patients were admitted to the hospital with severe injuries requiring extensive repair; another was dead on arrival at the emergency clinic. The retrospective study reveals a typical pattern to chain saw injuries as injuries caused by other power tools have typical patterns: the majority of the injuries occur on the left side. Most injuries are caused by saw kickback, upward or downward; the face (not usually eyes), neck, hands and feet are most frequently injured. The findings suggest that many of these extensive, expensive injuries can be prevented by proper equipment and training, and by operator compliance with safety procedures. An automatic motor brake is now being installed on many saws, and laws are being prepared to make its use mandatory.