Self-reported and observer-rated signs and symptoms of nicotine withdrawal were assessed precessation and 2, 7, 14, 30, 90, and 180 days postcessation in smokers who quit on their own for 30 days. Anxiety, difficulty concentrating, hunger, irritability, restlessness, and weight gain increased, and heart rate decreased, postcessation (p less than .001). Except for hunger and weight gain, these symptoms returned to precessation levels by 30 days postcessation. Craving, depression, and alcohol or caffeine intake did not reliably increase. Postcessation depression, but not withdrawal symptoms, craving, or weight gain, predicted relapse. These results are consistent with prior studies.