Importance: Heavy drinking among young adults is a major public health concern. Brief motivational interventions in the emergency department have shown promising but inconsistent results.

Question: Does a newly developed brief motivational intervention help patients aged 18 to 35 years presenting to the emergency department with alcohol intoxication reduce heavy drinking and alcohol-related problems more than brief advice?

Findings: In this randomized clinical trial, brief motivational intervention maintained a statistically significant lower number of heavy drinking days over 1 year compared with brief advice. No effects on alcohol-related problems were found.

Meaning: These findings suggest that a brief motivational intervention model implemented in the emergency department among intoxicated young adults can have a beneficial effect on heavy drinking, which is a major public health concern.