The success that drug courts have enjoyed to date rests on a foundation of collaboration among the legal, treatment, and law enforcement communities. Helping to build effective jail-based treatment programs can broaden and strengthen this foundation. Many drug courts rely on their local jails to incarcerate defendants prior to the start of their drug court program or to house defendants briefly as a sanction. Local jails provide an excellent setting for screening, assessment, delivery of initial treatment services, social detoxification (stabilization), and forging links with community treatment programs. In building a working model for effective jail-based treatment programs with functional linkages to local drug courts, several issues must be considered. Among them are communication between jail and drug court, treatment staffing, program space, experience and training, programming, jail staff assignment, follow-up services, and re-entry into the community. Regarding the latter issue, by acting as a re-entry court, drug courts can provide incentives for participants to complete jail-based treatment, a strong structure for defendants leaving jail, a continuum of treatment services, and a high level of probationer accountability. Appended descriptions of existing drug court and jail-based treatment linkages and 21 references