The objective of the study was to assess the occurrence of different procedures of upper airway surgery and estimate their relationship to specific upper respiratory tract infections and constitutional factors. In a population-based cross-sectional study in Oslo. Norway, of 3,763 preschool children 3 to 4 years of age, the otolaryngological surgeries adenoidectomy, tonsillectomy, myringotomy, ventilation tube insertion, and combinations of these were the outcome measures. The results showed that by 4 years of age, 13% (n = 501) had undergone operation, and approximately two thirds of the operations involved middle ear surgery. Although surgery was related to the occurrence of upper respiratory tract infections, the type of surgery was not related to the specific infection. In the children with operations, the occurrence of recurrent otitis media (> or = 3 infections in the previous 12 months) was almost fivefold higher than in children without operations (adjusted adds ratio [ORadj] = 5.19 [3.15 to 8.54]). A low level of maternal education (ORadj = 1.61 [1.05 to 2.7] compared to the group with a high level of education) and atopy on the part of the child (ORadj = 1.58 [1.20 to 2.07]) increased the probability for upper airway surgery independently of the experience of infections. In conclusion, early pediatric otolaryngological surgery is common. The decisions for surgical treatment vary substantially and are not closely related to the specific infections. The influence of other factors such as maternal education indicates that decisions for surgery are not entirely based on medical evidence.