This report describes retention in treatment in the National Institute on Drug Abuse Collaborative Cocaine Treatment Study (CCTS), a multi-site trial of four psychosocial treatments for 487 cocaine dependent patients. Younger, African-American, and unemployed patients were retained in treatment for fewer days than their counterparts. African-American patients who lived with a partner were retained in treatment for less time than if they lived alone. Higher psychiatric severity kept men in treatment longer but put women at risk for dropping out sooner. Patients who completed the full treatment used drugs less often than patients who dropped out, but outcome did not differ at each month. Patients in the drug counseling condition stayed in treatment for fewer days than patients in psychotherapy, but they were more likely to be abstinent after dropout. Patients with higher psychiatric severity were more at risk for continuing to use drugs after dropout.