The aims of this study are: 1) to investigate the occurrence and nature of children's suicidal thoughts and gestures; 2) to study the related factors in parental diagnostic characteristics and 3) to compare the clinical, developmental, demographic, age, and gender characteristics of suicidal and nonsuicidal children. The subjects are participants in a longitudinal study of families of bipolar (n = 21), unipolar depressed (n = 48), and well parents (n = 40) . Pairs of siblings in each family were studied. The children were interviewed at three periods, between 5 and 15 years of age. The data for these analyses are the child's expressed thoughts and/or plans about hurting him/herself or wishing to die. Parents were administered the SADS at the same three periods. Preliminary analyses based on the first two assessments indicate, as expected, that the preponderance of children from all groups show no suicidal symptoms in early and middle childhood. Percentages of the older sibling children, at ages 5 to 7 years, who did report suicidal ideation at Time 1 were 13%, 27%, 24% of the controls, unipolars, and bipolars, respectively. Those who reported that they had thought of a method or made an attempt were 11%, 14%, and 9% of controls, unipolars, and bipolars, respectively. At Time 2, when these older sibling children were 8 to 11 years of age, percentages who reported ideation were 28%, 28%, and 27%, controls, unipolars, and bipolars, respectively. Those who specified a method or attempt were 7%, 8%, and 16%, controls, unipolars, and bipolars, respectively. At Time 2, percentages of younger sibling children (age 5 years) who did report suicidal ideation were 12%, 24%, and 6%, controls, unipolars, and bipolars, respectively. Those who reported that they had thought about a method or made an attempt were 5%, 6%, and 4%, controls, unipolars, and bipolars, respectively.