This study measured effectiveness of behavioral day treatment plus abstinence contingent housing and work therapy (DT+) versus behavioral day treatment alone (DT). A randomized controlled trial assessed participants at baseline, 2 and 6 months. Participants (N=110) met criteria for cocaine abuse or dependence, non-psychotic mental disorders, and homelessness. DT+ achieved greater abstinence at 2 and 6 months and more days housed at 6 months than DT. Effectiveness of DT+ was demonstrated, with greatest impacts on abstinence outcomes. Results replicated earlier work demonstrating effectiveness of behavioral day treatment and contingency management as an effective combination for cocaine abusing homeless persons. Copyright (C) 2000 Elsevier Science Ireland Ltd.