Despite the economic importance and hazardous nature of commercial logging in various regions, few medical studies have examined fatalities in this industry. Data derived from the files of the Ontario Chief Coroner's Office revealed 52 deaths, all men, from 1986 to 1991 in the province of Ontario. Forty-four cases were accidents (age range 20-73 years; average, 44 years), the majority involving experienced loggers. Personal error resulting in preventable unsafe work practices was a factor in most accidents (n = 35; 79.5%). Almost one half of injured workers were struck by either dead or cut trees. Although the majority of cases occurred in remote areas, delayed medical attention as a factor contributing to death was uncommon. Many of the injuries were nonsurvivable and most victims (n = 33; 75%) were dead at the scene. Most deaths were caused by either head and neck injuries (n = 20; 45.5%), multiple trauma (n = 10; 23%), chest trauma only (n = 6; 13.5%), or mechanical asphyxia (n = 5; 11%). Blood alcohol was negative in 24 accident victims tested. Eight deaths (age range 42-52 years; average, 49 years) were due to cardiac causes, mainly ischemic heart disease. Disease may have contributed to two accidents.