HIV+ persons confront a unique set of challenges and chronic stressors, including stigmatization, alienation from family and friends, complex treatment regimens, and, often, debilitating side effects as they attempt to manage the psychologic and physiological consequences of their condition. For persons living with HIV, elevated distress and low social support take on added importance because they can accelerate disease progression. Helping HIV+ people to reduce stress and adhere to their medical care may in turn help to reduce their risky behavior. The ability to cope successfully with a chronic illness such as HIV disease is influenced by a number of social and psychological factors. Stress and coping theory provides a framework for studying these factors and for intervention. Coping research draws attention to the co-occurrence of positive and negative psychological states and recognizes the importance of encouraging coping processes that help to sustain positive psychological states in the context of stress. We evaluated a coping intervention, Coping Effectiveness Training (CET), designed to assist HIV+ gay men in sustaining psychological health despite the ongoing stress associated with HIV infection. The study was a randomized clinical trial of an innovative, theory-based coping intervention. The research questions addressed the problems of maintaining intervention effects, evaluating intervention effects on quality of life, health care utilization and adherence to medical care, and testing new advances in stress and coping theory.