The long-term results of surgical treatment for pediatric cholesteatoma are variable and there is no consensus on operation methods and on factors affecting outcome of surgery. We analyzed the independently evaluated long-term results and possible reasons for recurrence of cholesteatoma. A total of 84 consecutive pediatric (age < 16 years) cholesteatoma operations in the Helsinki University Central Hospital ENT Department. The operations were not staged, and all mastoids were obliterated and bony ear canals reconstructed without open cavities. The pre- and postoperative and annual control data were recorded in a database. The last control was independently performed (JS) with an average follow-up of 4.8 years and 87% attendance. The total recurrence rate was 29% (24/84), and it was not dependent on the size of cholesteatoma, mastoid status, cholesteatoma in the window niches or stapedial erosion. A retraction process developed in 25% (21/84) of the ears and 42% (9/21) of these turned into retraction pocket cholesteatomas as late as 13 years postoperatively. Retractions and postoperative discharge, especially in combination, predisposed to recurrence. Of the healed ears, 37% became atelectatic. Hearing was maintained on the preoperative level. Reduced middle ear and attic ventilation led to retractions, and atelectasis and a tendency to discharge accelerated the process. Pitfalls in mastoid obliteration and attic reconstruction and the failure to create new ventilation routes were important reasons for recurrence of cholesteatoma.