Objective: To analyze the long-term safety of mastoid obliteration with cartilage in children with suppurative cholesteatomatous ears. Methods: The medical records of children (≤18 years) with cholesteatomas after primary tympanomastoidectomies were performed with cartilage obliteration over a 30-year period (1982-2012) were analyzed. The recidivism rate was calculated using the Kaplan-Meier survival analysis. Potentially confounding factors of recidivism were entered into a Cox regression model as covariates for multivariate analysis. Results: Of the 150 cholesteatomatous ears in 146 children, there were 95 discharging ears (63%) in 94 children. Among the 95 discharging ears, tympanomastoidectomy was performed with cartilage obliteration (CO group) in 77 ears (81%) and without cartilage obliteration (WO group) in 18 ears (19%). The mean follow-up period was 12 years. Recidivism was observed in 16 ears in the CO group and 4 ears in the WO group. The 10-year cumulative recidivism rates were comparable between the CO and WO groups (19 vs. 25%, p = 0.762). Multivariate analysis confirmed that mastoid obliteration was not a negative predictor of recidivism (p = 0.760). Recidivism of cholesteatoma was detected within 6.5 years after surgery in the WO group and was found as late as 16.1 years after surgery in the CO group. Cartilage could be maintained in the cavity with limited resorption, preventing reretraction pockets and subsequent recidivism. Conclusion: This study provides evidence supporting the long-term safety, feasibility and effectiveness of mastoid cartilage obliteration for children with suppurative cholesteatomatous ears. Despite comparable recidivism rates between the groups, the potential for the delayed detection of recidivism with cavity obliteration may warrant long-term follow-up, with careful attention paid to the potential for recidivism during postoperative care in children. i 2014 S. Karger AG, Basel