Background: Testicular cancer with retroperitoneal metastases is often treated with chemotherapy, with subsequent post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) performed for residual masses after chemotherapy. While the cure rate is high, the surgery is associated with significant morbidity. Unlike in other genitourinary cancers, perioperative nutritional optimization is typically not prioritized as most patients are young, otherwise healthy men. Albumin is a systemic marker of nutritional status and has been shown to predict adverse outcomes in other urological cancers. We sought to assess whether preoperative albumin level is associated with postoperative outcomes in patients undergoing PC-RPLND. Methods: A database of patients who received PC-RPLND at our institution between 2007 and 2019 was created. Pre-RPLND albumin was obtained and correlated with postoperative outcomes using univariate and multivariable regression models. The primary outcome was the presence of major (Clavien-Dindo grade ≥ III) complications within 90 days of surgery. Results: Of 76 patients who underwent PC-RPLND, 70 patients had preoperative albumin values available. The median age (IQR) of patients at the time of surgery was 26 years (22 - 32) and median (IQR) preoperative albumin level was 4.4 g/dL (4.1 - 4.6). Patients with major postoperative complications had lower median preoperative albumin than those without a complication (4.1 g/dL vs. 4.4 g/dL; p = 0.03). Greater albumin level (per g/dL) was associated with a lower risk of major postoperative complications on multivariable logistic regression (OR = 0.12; p = 0.03). Other preoperative serum markers such as hemoglobin and creatinine did not associate with postoperative complications. Conclusions: To our knowledge, this is the first study to demonstrate that preoperative albumin is an independent predictor of major postoperative complications in patients undergoing PC-RPLND. This finding demonstrates the importance of nutritional optimization even in young, otherwise healthy individuals prior to undergoing this morbid surgery. Additional studies are warranted to more reliably predict which patients may experience complications.