Introduction and Objectives: To evaluate the utility of the GreenLight-SIM™ (GL-SIM) simulator to assess photoselective vaporization of the prostate (PVP) skills of urology postgraduate trainees (PGTs) during Objective Structured Clinical Examinations (OSCEs). Methods: After obtaining ethics approval, PGTs in Post- Graduate Years (PGY-3 to PGY-5) from all four Quebec urology training programs were recruited during two annual OSCEs. During a 20-minute OSCE station, PGTs were asked to perform two exercises: identification of endoscopic landmarks and PVP of a 30 g normal prostate. Grams vaporized, global scores and number of correct anatomical landmarks were recorded and correlated with PGY level, practice on the GL-SIM and previous PVP experience. Results: 25 PGTs were recruited at each OSCE with 13 PGTs participating in both OSCEs. When comparing scores from the 1st to the 2nd OSCE, there was a significant improvement in the number of grams vaporized (2.9 vs. 4.3 g; p = 0.003) and global score (100 vs. 165; p = 0.03). There was good correlation between the number of previously performed PVPs and the global score (r = 0.4, p = 0.04). Similarly, PGTs with previous practice on the GL-SIM had significantly higher global score (100.6 vs. 162.6; p = 0.04) and grams vaporized (3.1 vs 4.1 g; p = 0.04) when compared with those who did not practice on GL-SIM. PGY level did not significantly affect grams vaporized and global score (p > 0.05). Conclusions: Performance on the GreenLight-SIM at OSCEs significantly correlated with previous practice on the GL-SIM simulator and previous PVP experience rather than PGY level. Source of Funding: None