Post-event processing (PEP) involves a negative, self-focused review of one’s performance in past social events. PEP is common in social anxiety (SA); by increasing anticipation of failure for future social events, PEP serves to maintain anxiety. Research is needed to clarify the association between SA and PEP in the context of alcohol use, given that although socially anxious individuals are at increased risk of drinking problems, this risk pathway is poorly understood. To help resolve this, the present two studies aimed to assess the role of PEP in the link between SA and alcohol use among two samples of young adults who ranged in SA severity. Study 1 used a 3-week diary (via smartphone) to assess alcohol intoxication during, and PEP after, social events in a sample of individuals (N=92) high (n=40) and low (n=52) in SA. Of interest was the association between PEP and next-event intoxication, and the moderating effect of SA. Compared to the low SA group, those high in SA reported more PEP, similar intoxication, and a positive correlation between PEP and next-event intoxication. In the low SA group PEP and intoxication were unrelated. Multilevel models supported a SA by PEP interaction in the high SA group only. Specifically, increases in PEP corresponded with increases in intoxication at the next event, but only for those moderately high in SA. Study 2 used a lab-based procedure, and participants (N=103) consumed alcoholic (n=52) or non-alcoholic (n=51) beverages, engaged in an anxiety-provoking interaction, and completed follow-up assessments of PEP about the interaction (sent via email). Regression models supported a SA by drinking status interaction in predicting PEP in the alcohol condition only. Specifically, for those who consumed alcohol before the interaction, elevated (baseline) SA was associated with increased PEP, but only for light drinkers. For heavy drinkers in the alcohol condition, SA was unrelated to PEP. These results underscore the importance of PEP, and variables that influence PEP, in understanding the link between SA and alcohol use. The results are discussed in terms of theoretical and clinical considerations.