BackgroundPredictors of outcomes in pediatric microtia surgery are not well understood within the current literature. A multi-institutional database study may reveal insights into these predictors. ObjectivesTo explore predictors of 30-day complications, 30-day readmission, and postoperative length of stay (PLOS) in pediatric microtia patients undergoing autologous rib grafting. MethodsThe Pediatric National Surgical Quality Improvement Program was queried for patients with microtia (ICD-9/10 744.23/Q17.2) who underwent autologous rib grafting (CPT 21230) between 2012–2021. Demographics, comorbidities, inpatient status, 30-day complications, PLOS, and 30-day readmissions were analyzed. Statistical analyses were performed to compare preoperative characteristics with postoperative outcomes. Results667 patients met inclusion criteria. 63 (9.4%) had at least one complication and 19 (2.9%) were readmitted. Univariate analysis showed inpatient status (p=0.011) and race (p=0.023) were associated with higher complication rates. Multivariate analysis revealed that outpatient status was associated with significantly lower odds of complications (OR: 0.49, 95% CI [0.27, 0.87], p=0.018), and developmental delay was associated with higher odds of 30-day readmission (OR: 2.80, 95% CI [1.05, 7.17], p=0.036). Longer operative time was associated with older age (13.9% increase per five-year age increase, p<0.001) and inpatient status (35.3% increase, p<0.001). Postoperative length of stay was shorter for outpatients (45.45% shorter, p<0.001) and cases performed by plastic surgeons (14.2% shorter, p<0.001). ConclusionMicrotia reconstruction with autologous cartilage is a relatively safe procedure with low complication and readmission rates. Significant predictors of postoperative outcomes include inpatient status, race, developmental delay, and age. These findings highlight the importance of considering these factors in surgical planning and patient counseling.