The analysis used trivariate probit estimates based on all 7,883 defendants arrested between June 1984 and January 1985. Results revealed that the successful participants in the pretrial urine-testing program had rates of pretrial rearrest, failure to appear, and overall pretrial misconduct that were about one half the rates for individuals who failed to show up for the urine testing or who dropped out after only a few tests. The urine-testing program is operated by the District of Columbia Pretrial Services Agency (PSA). PSA collects urine specimens from arrestees shortly after arrest, testing for the presence of opiates, cocaine, phencyclidine (PCP), amphetamines, and methadone. Defendants identified by this testing or by self-reports as drug users are usually released nonfinancially to await trial and are often required to enter either drug treatment or periodic urine testing before trial. Figure, tables, notes, and 14 references (Author abstract modified)