Alcohol misuse among college students is a persistent public health problem. Identifying the circumstances which influence alcohol misuse can inform the development of interventions to reduce risk for adverse outcomes in this population. Prior research suggests that people who engage in unplanned drinking report more alcohol-related consequences, and that unplanned heavy drinking is associated with consequences at the within-person level. The present study involved exploration of the within-person relationship between drinking events that were unplanned (vs. planned) in the morning and later quantity consumed, negative and positive consequences, and overall event evaluations. College student drinkers (N = 96) provided data on their drinking experiences each morning during a 28-day ecological momentary assessment study. Hierarchical linear models revealed that unplanned drinking events were associated with lower alcohol quantity, fewer alcohol-related consequences, and lower ratings on how "worth it" the drinking event was, compared to planned events. In contrast to prior work highlighting the risk associated with unplanned heavy drinking, our findings indicate that drinking events that are planned (vs. unplanned) are related to increased consumption and the experience of negative consequences. Additional research is needed to more definitively assess the differences between planned and unplanned drinking events and their relationship to adverse alcohol-related outcomes among college students. (PsycInfo Database Record (c) 2020 APA, all rights reserved).