Results of the study indicated perceptions of heavy drinking were higher than the current 5-drink definition for “binge” or “heavy episodic” drinking. However, these perceptions appeared to be dynamic, varying as a function of gender, drinking situation, target occupation, and participants’ drinking behaviors. Results also suggest that students may not intervene with regard to their own or a peer’s drinking until that drinking becomes quite excessive. Future research is recommended to examine factors affecting perceptions of drinking behaviors. The debate over how to best classify drinking, particularly heavy and problem drinking has raised the question: what do college students perceive as heavy and problematic drinking? Two-hundred and twelve college students read a vignette about a 21-year old male described as a college student or a retail management trainee drinking at a bar alone or with friends. Participants also provided estimates of the number of drinks and drinking occasions they thought would signify a drinking problem for the target. Notes, references, table, and figures