On 4 days, in everyday situations, 21 female and 26 male smokers used an electronic diary to record situations and moods at times of smoking and at control nonsmoking occasions. Self-reports of particular locations, activities, posture, consumption, social context, moods, and internal states were specifically associated with smoking. Real-time assessments in everyday situations provide useful information about the interplay of environmental factors and internal states in smoking. The findings suggest that conditioning and learning processes play a role in smoking and should be considered in smoking cessation programs.