Smoking cessation rates, progression in stage of change for smoking cessation, and serious quit attempts were examined over 2 years in a cohort of 242 men and women smokers (mean age 39.7 years, mean body mass index [BMI] 26.3) as a function of expressing concern about gaining weight because of quitting smoking. Participants were employees of 25 companies who were in a worksite health promotion program aimed at reducing risk factors for cardiovascular disease. Multivariate odds ratios (controlled for age, education, job class, sex, and BMI) for quitting smoking, attempting to quit smoking, and progressing in stage of change for smoking cessation as a function of weight concern were not significant. Interactions between sex and weight concern, and BMI and weight concern were also not significant. These findings, in a working, predominantly blue-collar population, and those of other studies, suggest that concern about gaining weight is, at best, a weak predictor of change in smoking behavior among most smokers.