The use of guns as a suicide method in Toronto is described for the same period, and data are presented on suicide methods in San Diego, California, from an investigation of 283 suicides that occurred between November 1981 and June 1983. There was no statistically significant change in the mean total suicide rates for Toronto and for all of Ontario for the five preceding years and the five years after 1978. A significant decrease occurred in the mean proportion of suicides by shooting for the men in Toronto accompanied by a significant increase in the mean proportion of men who committed suicide by leaping. Only two percent of the women used guns for suicide during each time period. Among the women in the San Diego study, only 17 of the 61 in the consecutive series, 13 of the 34 in the under-age 30 series, and 11 of the 47 women in the age 30 and older series had used a gun. There were no significant differences among these groups in the proportion of women who had been hospitalized for psychiatric disorders compared to proportion who had never received psychiatric treatment. A significantly smaller proportion of the 88 men in the consecutive series and the 51 in the under-age 30 series who had used guns to commit suicide had been hospitalized for psychiatric disorders than had never received psychiatric treatment. The data from both Toronto and San Diego suggest a substitution of method would occur if the availability of guns was restricted significantly. 3 tables, 35 references.