Introduction Unplanned reoperation (URO) and unplanned hospital readmission (UHR) are key quality indicators used to assess healthcare quality improvement. The aim of this study was to describe, quantify, analyze and compare both indicators in a Pediatric Surgery Department. Methodology An observational study was conducted reviewing the medical records of pediatric patients who underwent unplanned reoperation and unplanned hospital readmission over a six-year period in a pediatric surgical unit. The incidence, indications, and causes of reoperations and readmissions were analyzed. Results A total of 6,376 surgeries were performed over a six-year period. During this time, there were 37 (0.58%) URO and 20 (0.31%) UHR. There were 23/2,437(0.94%) URO and 14/2,437(0.57%) UHR among emergency surgeries. In contrast, there were 14/3,939(0.35%) URO and 6/3,939(0.15%) UHR among elective surgeries (p < 0.05). Outpatient surgeries had 3/1,639 (0.18%) URO and 1/1,639 (0.06%) UHR compared to inpatient surgeries that had 11/2,300(0.47%) URO and 5/2,300 (0.21%) UHR respectively (p = ns). A total of 1,570 appendectomies were performed during the study period, with 8/1,570(0.5%) patients requiring either a URO or a UHR. The most frequent indication for both URO and UHR were intra-abdominal infections. The main cause of URO was a technical error during surgery (70%), while the main cause of UHR was an error in the medical treatment (35%). Conclusion In our practice, URO are more frequent than UHR. Emergency surgeries have a higher risk of undergoing an URO or a UHR. Acute appendicitis is the most common diagnosis associated with the need for an URO or a UHR. The majority of unplanned reoperation cases are due to technical errors during surgery.