Very little of the professional literature on suicide deals with suicide in jails, and virtually no references to juvenile suicide in adult jails exist. To determine if the rate of juvenile suicide in adult jails might be higher than that in secure juvenile detention centers, suicidal conduct was used as the indicator of the harmful effects of placing children in adult jails. The sample included all juvenile detention facilities, sampling of jails with an average daily population (ADP) of fewer than 250 inmates, a full sample of those with an ADP of more than 250, and lockups. Questionnaires (N=913) were sent to the lockups in the sample. Data indicated that, during 1978, approximately 392,662 juveniles occupied adult jails and lockups. Results supported the hypothesis that the rate of suicide among juveniles held in adult jails and lockups was significantly higher than that among children in juvenile detention centers and children in the general population. However, the data did not indicate that the suicide rate among youth placed in juvenile detention facilities was greater than that of children in the general population. These results suggest that the policy of incarcerating children in adult jails may be contributing to the relatively high rate of suicide. (RC)