The present experiment examined effects of nicotine on body weight of male and female rats when Oreo cookies, potato chips, laboratory chow, and water were available. Body weight and eating behavior were measured for 17-day periods before, during, and after nicotine or saline administration. There was an inverse relationship between nicotine and body weight. These effects were paralleled by changes in consumption of sweet foods. There were no effects of nicotine on salty or bland food consumption. Excessive gains in body weight after cessation of nicotine administration were greater for females than for males.