The current study examined the moderating influence of observed parental emotion socialization (PES) on self-medication in adolescents. Strengths of the study include the use of a newly developed observational coding system further extending the study of PES to adolescence, the use of an experience sampling method to assess the daily covariation between negative affect and substance use, and a focus on PES styles defined by the interaction of emotion-dismissing and emotion-coaching behaviors. Using multi-leveling modeling, we tested PES as a moderator of daily negative mood-substance use relation in a sample of 65 elevated-risk adolescents (48% male, 58% Caucasian, with a median age of 14). Results showed a three-way interaction between emotion-coaching PES, emotion-dismissing PES and daily negative mood in predicting daily substance use. Results are discussed in terms of the importance of PES styles and their effects on self-medication through compromised emotion regulation and interpersonal processes.