Canadian Bill C-17 was implemented in 1991 to restrict the use of firearms, providing a chance to investigate the effect of firearm control laws in the use of firearms for suicide and homicide. Following Lester and Leenaars' comprehensive studies, the present study examined the use of firearms for suicide and homicide during the period prior to the bill and during the period after the passing of Bill C-17 to assess the association of the bill with rates of suicide and homicide by method. Analysis showed a significant decrease after passage of Bill C-17 in the rates of suicides and homicides involving firearms and the percentage of suicides using firearms. The analysis provides support for the position that restricting the availability of firearms as a lethal means of committing suicide and homicide may help reduce the numbers of suicides and homicides.