The research considered the following rationales: (1) that monitoring enhances the restrictiveness of pretrial supervision and (2) that drug test results are thought to be useful predictors of pretrial flight or crime. At both research sites, the research design included a pre-post comparison of defendants to examine any effect the program might have on judicial decisionmaking, and an experimental phase to determine the impact of the drug monitoring program on defendant misconduct. Results indicated that, despite sanctions, program compliance by defendants was generally poor. At both sites, the programs reached only a small proportion of the eligible defendants, partly because of the voluntariness of initial testing and partly because of the role that drug test information had in the overall determination of bail. In both sites, the planned tariff of sanctions was not implemented, partly because the courts were unprepared for the court time required for enforcing conditions or unwilling to devote sufficient judicial resources to reviewing the status of noncompliant defendants. Finally, without the crucial element of sanctions being applied, no significant differences existed between the tested and nontested groups for either pretrial flight or crime. Tables, figures, and 17 references