BACKGROUND: The readmission rate after pediatric appendectomy is frequently reported in clinical outcomes studies and quality improvement initiatives without proper description. Our aim was to delineate the context and significance of these encounters. METHODS: Patients (<18 years old) who underwent appendectomy for acute appendicitis at a tertiary children's hospital from January 2007 through June 2010 were reviewed. Emergency department (ED) visits and inpatient readmissions within 90 days were identified and classified as unrelated, related surgical complications, or potentially avoidable visits for minor related concerns. RESULTS: Of 629 patients, 119 (18.9%) had 141 ED visits or readmissions within 90 days after discharge. Eighty-three (58.9%) encounters were limited to the ED, and 58 (41.1%) required inpatient hospitalization. Eighty-seven percent of encounters within the first 30 days after discharge, but only 26% of those occurring beyond 30 days, were related to the operation (P < .001). Overall, 45 (31.9%) ED visits or readmissions were totally unrelated to the appendectomy, 36 (25.5%) represented true surgical complications requiring inpatient hospitalization, and 60 (42.6%) were minor, potentially avoidable visits related to the appendectomy. Potentially avoidable encounters were more common in Spanish-speaking patients (P < .01). CONCLUSIONS: Emergency department visits and inpatient readmissions after pediatric appendectomy are frequent but not uniformly indicative of surgical complications or suboptimal care. Opportunities exist to reduce avoidable ED visits related to minor postoperative concerns.