The National Heart, Lung, and Blood Institute supports a variety of research programs related to smoking as a risk factor in cardiovascular and pulmonary disease. These programs include epidemiologic and toxicological studies, as well as research on educational and health behavior interventions. The objective of this program announcement is to encourage research activities which will clarify the influence of psychosocial stressors on smoking, smoking cessation, and the maintenance of cessation. It has been hypothesized that cigarette smoking may function as a stress-reducing or coping behavior for certain individuals. These individuals apparently increase their smoking behavior in stressful circumstances; if they have stopped smoking, there is a tendency toward relapse in such circumstances. The data in support of this hypothesis have been derived from several sources, but lack sufficient integration to provide a comprehensive and definitive statement concerning the nature of the stress--smoking interaction. Further research is needed to clarify this issue and to provide practical direction for smoking cessation programs. Examples of relevant questions include: (1) Can the extent to which an individual relies on smoking to cope with environmental and social stressors be used as a predictor for the most appropriate cessation approach? (2) Can appropriate strategies be developed for training smokers in the use of alternative coping behaviors as a means of enhancing smoking cessation and cessation maintenance (e.g., stress management training)?