This study investigated the relationship between frequency of heavy episodic drinking and nonfatal injury in four categories: environment, external cause, diagnosis, and activity at the time of injury. Data were collected over 18 months at the emergency room facility of a Swedish hospital. Injury patients aged 18-70 years answered an alcohol screening questionnaire. Heavy episodic drinking was measured as drinking six glasses (72 g alcohol) or more per occasion, for both males and females. A total of 2211 patients were enrolled in the study (79.5% completion rate). Demographic and drinking characteristics for the patients were compared to those of the general population, data for which were derived from a population-based survey. The proportion of people who reported heavy episodic drinking once a month or more was nearly twice as large among the injury patients as in the general population. However, age and sex outweighed heavy episodic drinking as risk factors for most injury types. There were 11 significant associations between frequency of heavy episodic drinking and injury types in the four injury categories, yet no linear trends of increased likelihood of injury with increased frequency of heavy episodic drinking could be discerned.