Up to 6% of men who undergo vasectomy may later undergo vasectomy reversal. Most men require vasovasostomy but a smaller subset requires epididymovasostomy. Outcomes of epididymovasostomy depend highly on specialized training in microsurgery and, if predicted preoperatively, might warrant referral to a specialist in this field. We created a nomogram based on preoperative patient characteristics to better predict the need for epididymovasostomy. We evaluated patients who underwent primary vasectomy reversal during a 5-year period. Preoperative and intraoperative patient data were collected in a prospectively maintained database. We evaluated the ability of age, years since vasectomy, vasectomy site, epididymal fullness and granuloma presence or absence to preoperatively predict the need for epididymovasostomy in a given patient. The step-down method was used to create a parsimonious model, on which a nomogram was created and assessed for predictive accuracy. Included in the study were 271 patients with a mean age of 42 years. Patient age was not positively associated with epididymovasostomy. Mean time from vasectomy to reversal was 9.7 years. Time to reversal and a sperm granuloma were selected as important predictors of epididymovasostomy in the final parsimonious model. The nomogram achieved a bias corrected concordance index of 0.74 and it was well calibrated. Epididymovasostomy can be preoperatively predicted based on years since vasectomy and a granuloma on physical examination. Urologists can use this nomogram to better inform patients of the potential need for epididymovasostomy and whether specialist referral is needed.