Friendship-related stress is an understudied factor that may explain variation in coping-motivated and socially-motivated drinking among emerging adults. This study examined chronic and episodic friendship stress as predictors of drinking levels and motivations among emerging adults transitioning to post-college life. College drinkers reported drinking motives and alcohol consumption daily for 30 days using an Internet-based diary in college and five years later (N = 897, 54.2% women, Mage = 24.6 at follow-up, 86.0% White). Post-college, participants completed by phone the UCLA-Life Stress Interview assessing chronic and episodic friendship/social life stress. Chronic friendship/social life stress was positively correlated with mean levels of post-college drinking-to-cope motivation and was negatively related to post-college heavy drinking and social drinking motivation. Emerging adults experiencing friendship stress are more likely to use alcohol as a coping mechanism, elevating their risk for alcohol-related problems. Those with low friendship stress may require public health interventions around the risks of heavy drinking.