Marijuana is the second most commonly used substance in the US. A growing literature suggests that socially anxious individuals use marijuana to manage their symptoms in social situations, which may explain why they are also more likely to experience problems. Unfortunately, the majority of the literature is based on research conducted with adult samples or the co-occurrence of diagnoses in adolescent samples. The proposed study sought to test the link between social anxiety (SA) and proxies for ‘real-time' marijuana use behaviors (i.e., use willingness) as well as use-related problems among adolescents. Participants were 69 adolescents (15-17; 55% female) recruited from the community reporting any lifetime marijuana use. Participants were randomly assigned to a novel social rejection or neutral laboratory task and completed measures of SA, marijuana use frequency, and related problems. Consistent with adult findings, main effects of SA and experimental condition on marijuana use willingness were expected to be qualified by an interaction in which the greatest marijuana use willingness would occur among high SA youth post-rejection (H1), SA would be positively related to marijuana use problems (H2), and among adolescents in the rejection condition, marijuana use willingness would be positively correlated with use problems (H3). Only H2 was …