Parents, public health officials, college personnel, and society at-large continue to be concerned about the increase in heavy drinking that occurs across the transition to college, prompting alcohol researchers to continue the search for effective interventions. In this report we use data from a large (N=3720) prospective study to (1) estimate how predictable heavy drinking in the first semester of college is on the basis of information obtained prior to college and (2) identify precollege variables that are important predictors of heavy drinking in the first semester. We found that first-semester heavy drinking is highly predictable, primarily because of continuity from precollege heavy drinking, but also from precollege peer drinking norms, precollege other substance use (esp. tobacco use), and precollege party motivation for attending college. These findings have implications for both the timing and targets of interventions. Interventions timed to occur prior to college and/or in the early months of college may disrupt the momentum of previously established drinking behavior. Furthermore, interventions may be most effective if they target conjoint alcohol and tobacco use, college party motivation, and self-selection into heavy-drinking social environments.