Personality and physiological, cognitive, and environmental factors have all been suggested as critical variables in smoking cessation and relapse. Weight gain and the fear of weight gain after smoking cessation may also prevent many smokers from quitting. A sample of 45 adult smokers participated in a study in which three levels of preventive weight control intervention (weight control discussion; discussion with monitoring of eating habits; and discussion, monitoring, and homework exercises), combined with smoking control treatment, were compared for effectiveness in producing smoking cessation and preventing weight gain during and following treatment. Results showed all participants indicated a posttreatment abstinence rate of 43%, a percentage lower than that found in previous studies. No signficant differences were found between the three treatment conditions in percentage of participants abstinent at 1 and 6 months posttreatment. A significant treatment effect was found for the intermediate treatment group which showed a 50% abstinence rate at 6 months posttreatment, compared to 15% and 29% for the other groups. Treatment condition was not found to affect body weight. Although treatment manipulation was expected to affect body weight, the absence of weight differences between groups may be related to the structure and social support the treatment groups provided to participants. (JAC)