The objective of this study was to determine trends in suicide rates in the general Icelandic population & among demographic segments of the population. The authors found that numbers of suicides & suicide rates in Iceland 1951-1990 follow a pattern of irregular waves. The average number of suicides grows over time, but the suicide rate is a stationary process. Suicide rates are higher for males in every five year age group, but the ratio of female to male suicides is curvilinear, peaking in the 50-69 year old age groups. Suicide rates within age groups are stable or decreasing over time except for males aged 15-24 & females aged 55-64. (20 refs)