Data were collected from all county jails and juvenile detention centers in the State and from those municipal lockups which have not reported having a policy against holding juveniles. In 1987 there were 7,969 secure detentions of juveniles, a 9-percent increase from 1986. The number of juveniles detained generally increased with increasing age. Over 82 percent of juveniles detained were males: one-half were white, and over 43 percent were black. Less than one-half of all juvenile detentions were for specific criminal code violations. Most of the remainder of detentions were for nonsecure custody-order violations, apprehension orders, or other violations. Fourteen percent of all detentions were for violent offenses, and 26 percent were for property offenses. The average length of detention in county jails was 6 days, and the average detention length for centers was 7.8 days. In county jails, one-half of the detentions were for 24 hours or less. In detention centers, slightly more than 28 percent of detentions were for 24 hours or less. 8 charts, 12 tables.