We have examined the implications of selecting children with otitis media with effusion (OME) for adenoidectomy using different criteria. Data were collected pre-operatively on 125 consecutive cases of OME. Ages 1-13 years, mean = 4.9 years; 68 males and 57 females. The criteria used were: (1) obstructive nasal symptoms, (with three sub-categories); (2) age: and (3) nasopharyngeal airway size. The three sub-categories of obstructive nasal symptoms were based on the clinical practices of colleagues in the UK. Thus we analysed five criterion groups in all. These were: (1) snoring; (2) snoring + mouth breathing; (3) snoring + nasal obstruction; (4) age = 4-8 years and (5) nasopharyngeal airway < 4 mm. We found that applying each criterion separately to the group of children would result in widely differing numbers of children being selected for adenoidectomy. Of the 125 children, the percentage selected by each method varied considerably, ranging from 35-70%. In addition, there was only limited overlap, (43-71%) between the composition of the groups. This helps to explain the variations in surgical rates in different centres. In the absence of any universally acceptable guidelines, therefore, the importance of individual assessment of children can not be overemphasised.