The basic goal of aftercare in drug abuse treatment is to prevent treated patients from returning to drug abuse. However, anywhere from 40 percent to 80 percent of the clients treated will relapse. Some relapses are more devastating than others due to health or personal safety risks. In addition, relapse is a predictable process, but clients can see it approaching only if they are extremely honest and self-aware. Recovery from crack and cocaine dependency is particularly difficult, because they affect individuals differently than other substances do. To help prevent relapse, treatment programs should use five strategies, including making recognition of the likelihood of relapse a focus of the treatment program, including treatment interventions designed to anticipate relapse, and enhancing the supportiveness of the post-treatment environment. They should also develop aftercare programs that offer continued contact with the client and interventions while in treatment that take into account the likelihood of drug substitution as a form of relapse. Table and 6 references.