Purpose: Retroperitoneal lymph node dissection (RPLND) for germ cell tumours is a challenging procedure that may present relevant complications. The purpose was to analyse postoperative complications and identify risk factors for major complications. Methods: This is a retrospective unicentric analysis of a large cohort of 295 RPLNDs from 1992 to 2020. Early complications (30 days) and late complications (31–180 days) were classified according to the Clavien‒Dindo classification. The influence of surgical, patient-specific, and tumour-specific parameters on grade III–V complications was analysed in univariate and multivariate logistic regression models. Results: A total of 232 were postchemotherapy RPLNDs, and 63 were primary RPLNDs. Early postoperative complications were found to be grades I–II in 58.6% (173/295), grades III–IV in 9.8% (29/295), and grade V in 0.3% (1/295). In 20% (58/295), additional surgical procedures were needed. Grade III–V complications were associated with ≥ 4 cycles of preoperative chemotherapy (OR 3.7 (1.5–8.9); p = 0.004), RPLND specimen (nonseminoma or immature teratoma) (OR 3.1 (1.4–6.6); p = 0.005), transfusions (OR 2.4 (1.1–5.4); p = 0.03), salvage RPLND (OR 4.1 (1.8–9.3); p < 0.001), and preoperatively elevated AFP (OR 5 (2.2–11.7); p < 0.001). In multivariate analysis, the only independent predictor for grade III–V complications was preoperative AFP elevation (OR 3.3 (1.2–9.2); p = 0.02). Limitations include the retrospective study design. Conclusions: Our results demonstrate that RPLND is a demanding surgical procedure. Patients with a complex tumour history have a higher risk of complications. We recommend treatment of these complex cases in high-volume centres.