The authors examined 3,335 cases of suicides among the unnatural deaths in Shiga Prefecture during the 15-year period, 1974 to 1988. The results obtained were as follows: The number of suicides in a year amounted to 200 during the period from 1974 to 1982, and increased to 280 in 1983 at maximum. The cases of suicide were more in male than in female. The incidence of suicide was higher in March to July and the peak of incidence was observed in April. The highest frequency of suicides was in 40-49 year age group in male, and 70-79 year group in female. Among various procedures of suicide, hanging was most frequent during the past 15 years in both sexes, and the following procedure was carbon monoxide poisoning in male and drowning in female. As to the occupation, housewives and person without a regular occupation constituted 53.1% of the total suicidal cases, and products makers and laborers were found in 11.1%. With regarded to the causative factors, "suffering from illness" was the most frequent factor, and followed by "insanity or mental disorder", "problems of economic distress", "disagreement with family" and others.