Objective: The NBME Psychiatry Subject Examination (PSE) is used throughout North America to test MS-III end-of-clerkship knowledge; yet, literature on PSE preparatory methods remains sparse. This study assesses the effect of a curriculum intervention on NBME PSE scores. Method: An optional 1.5-hour review session and accompanying fill-in-the-blank handout was offered to 62 MS-III students 3 days before their exam. Students who did not attend the session were e-mailed the handout with completed answers. The primary outcome measure was a change in scores, with students in the previous year serving as the control group. Results: The average raw PSE score of students offered the review session was 84.53, versus 77.15 for matched controls (p less than 0.0001). The effect size for the intervention was 0.89. Conclusion: This study may suggest that offering a comprehensive review session to third-year medical students 3 days before their NBME PSE significantly improves their scores.