OBJECTIVE: A novel educational tool, Computer Enhanced Visual Learning (CEVL), has been used to improve resident performance of routine orchiopexy. Our objective was to assess the effect of a CEVL teaching module on the diagnostic accuracy of medical trainees in grading neonatal hydronephrosis on ultrasound using the Society for Fetal Urology (SFU) grading system. METHODS: The authors designed an online-based computerized tutorial to teach the grading of hydronephrosis using multimedia, practice cases and a grading checklist. In a crossover design trial, 29 residents and medical students were asked to grade 16 standard neonatal renal ultrasounds using the SFU grading system before and after viewing the web-based e-learning module. Primary outcome was percent improvement in grading accuracy. RESULTS: The mean percentages of ultrasounds that were graded correctly before and after CEVL intervention were 51% and 72% respectively (mean improvement 21%, 95% CI 3-13%, P < 0.001). Residents graded correctly 56% of ultrasounds before and 74% after CEVL (mean 18%, 7-28%, P = 0.002). Medical students graded correctly 37% before and 69% after CEVL (mean improvement 32%, 95% CI 16-48%, P = 0.002). CONCLUSION: Exposure to a computer-based learning module based on the CEVL platform improved urology residents' and medical students' correct assignment of SFU hydronephrosis grading to newborn renal ultrasounds.