Many States have faced the problem of noncompliance with the Federal requirement that police not hold juveniles in custody for more than 6 hours, as long as the same facility is used to hold adults. To evaluate compliance with this requirement in Philadelphia, 1,870 randomly selected juvenile cases from December 1988 through July 1990 were evaluated based on quantitative data obtained from police records. Three types of record data were used: juvenile case flowcharts, arrest reports, and investigative reports. It was found that Philadelphia was not in compliance with the Federal 6-hour requirement; the mean time of juvenile lockup was 9.3 hours and ranged up to 57 hours. Prior implementation of a policy to fingerprint youth charged with felony offenses occurred without regard for the effect this added procedure would have on time in custody; fingerprinting alone nearly doubled time in custody. Other factors related to time in custody included unreadable fingerprints, transportation time to the identification unit, offense type, whether the youth was charged with a drug offense, offense seriousness, parental refusal to pick up children, and transportation delays to detention. Measures implemented by the Philadelphia Police Department reduced average time in custody by 50 percent. 43 references, 5 footnotes, and 6 tables