['To evaluate perioperative outcomes related to resident involvement (RI) in a large and prospectively collected multi-institutional database of patients undergoing orchiectomy for testicular cancer.', 'Using current procedural terminology and ICD-9 codes, information about patients with testicular cancer were abstracted from the American College of Surgeons National Surgical Quality Improvement Program database (2006-2013). Multivariable analyses evaluated the impact of RI on outcomes after orchiectomy. Prolonged operative time (pOT) and prolonged length of stay were defined by the 75th percentile (59 min) and postoperative inpatient stay ≥2 days, respectively.', 'Overall, 267 patients underwent orchiectomy either with (38.6%) or without (61.4%) RI. In all, 89.1% of patients underwent an outpatient procedure. The median body mass index was 26.8 and baseline characteristics between the 2 groups were similar. Overall complications, re-intervention, and bleeding-related complication rates were 2.6, 0.7, and 0.4%, respectively. Although there was no difference in terms of overall complications between the groups (3.9 vs. 1.8%; p = 0.44), RI resulted in pOT (32 vs. 19.5%; p = 0.028). In multivariable analyses, RI predicted pOT (OR 1.89, 95% CI 1.06-3.37; p = 0.031), without association with prolonged length of stay and overall complications.'] Does resident Involvement in Radical Inguinal Orchiectomy for Testicular Cancer Adversely Impact Perioperative Outcomes - A Retrospective Study?