© 2019 Elsevier Inc. Background: Hepatoblastoma and Wilms tumor are the most common primary liver and kidney tumor in children, respectively, and little is documented about patient outcomes in the immediate perioperative period. The aim of this study was to analyze the short-term outcomes of pediatric patients after surgical resection for hepatoblastoma and Wilms tumor. Methods: We queried the 2012-2016 ACS National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database for patients with hepatoblastoma who underwent liver resection and patients with Wilms tumor who underwent a partial or total nephrectomy. Patient demographics, preoperative, intraoperative, and postoperative characteristics were analyzed. Multivariate logistic regression was used to determine independent risk factors for unplanned reoperations. Results: There were a total of 189 patients with hepatoblastoma and 586 patients with Wilms in National Surgical Quality Improvement Program-Pediatric. The mean age of patients with hepatoblastoma was 3.1 y and 4.2 y in the Wilms group. Nine percent (n = 17) of patients underwent an unplanned reoperation after hepatectomy, and 4.1% (n = 24) of patients with Wilms experienced an unplanned reoperation. Over half of patients with hepatoblastoma (59.8%, n = 113) and 29.7% (n = 174) patients with Wilms tumor received a blood transfusion in the perioperative period. Patients in both groups demonstrated low rates of surgical site infections, but 6.3% (n = 12) of hepatoblastoma patients showed evidence of sepsis. Conclusions: This study will allow providers to more effectively counsel families of the common morbidities in the associated perioperative period following surgical resection of either solid tumor type including the substantial risk of blood transfusion.