The extent and predictors of weight change were assessed among sustained nonsmoking special intervention participants in the Lung Health Study. The intervention included a 12-session group program and 2-mg nicotine gum. At 12 months, female sustained quitters (SQs; n = 248) had gained a mean of 8.4% (5.3 kg) of their baseline weight, whereas male SQs (n = 443) had gained 6.7% (5.5 kg). By 24 months, female SQs had gained 9.8% of their baseline weight compared with 6.9% for men. Nicotine gum usage delayed a portion of the weight gain. Multiple regression analysis showed that weight gain at 12 months was associated with a higher baseline salivary cotinine level, a lower baseline body mass index, drinking less alcohol per week, and a lower cotinine level at 12 months (indicating less or no nicotine gum use). We conclude that moderate weight gain is a long-term consequence of smoking cessation--a portion of which can be delayed with 2-mg nicotine gum.