Surveys and electronic diaries were used to examine depressive and extemalizing dispositions as they relate to smoking and moods in 170 early adolescents. Negative moods were prevalent, with anger and anxiety reported on 26%-60% and sadness on 16%-40% of occasions. The risk of smoking, urges to smoke, and alcohol intake were elevated in teens with aggressive and depressive dispositions, as were diary reports of feeling hassled, angry, and sad. Girls high in depression and aggression also reported more anxiety, stress, and fatigue and less happiness and well-being than did their peers. For boys, depression seemed to dampen the elevated smoking risks associated with externalizing behaviors. Discussion focuses on gender differences in personality-smoking linkages, adolescent negative affectivity, the unique contributions of survey and diary methods, and the promise of targeted preventive interventions such as affect regulation training.