The research methodology involved a literature review, analysis of secondary data on suicides, and primary data collection from a random sample of 1,989 suicides in Ontario. Factors associated with suicide methods were evaluated, and provincial variations in firearm-related suicides were analyzed. The total number of firearms in private hands did not decline after gun control legislation was introduced in 1977. After passage of this legislation, however, firearm-related suicide rates leveled off or dropped in all Canadian provinces. The reduction in firearm-related suicides after 1979 was concentrated among younger age groups. Victims selecting firearms for suicide were likely to be disinhibited by alcohol consumption to the point of impairment but were not as likely to have a major or ongoing depressive illness. Canadian provinces with lower levels of gun ownership and firearm-related suicide rates did not have higher rates of nonfirearm-related suicides but did have lower overall suicide rates. Findings suggest that gun control legislation may have reduced suicide rates in Canada by causing a reduction in firearm-related suicides, particularly among males under 40 years of age. References, tables, and figures