We studied the efficacy of adenoidectomy in 213 children who had received tympanostomy-tube placement because of persistent and/or recurrent otitis media and had again developed otitis media after tubal extrusion. Ninety-nine of the children were assigned randomly to either an adenoidectomy group or a control group; in a separate trial, 114 children whose parents withheld consent for randomization were assigned according to parental preference. In both trials, control group outcomes appeared to have been biased favorably by the withdrawal of certain severely affected subjects from control status to receive adenoidectomy. Nonetheless, in both trials, adenoidectomy group outcomes were more favorable than control group outcomes during the first 2 follow-up years. Statistically significant differences were found mainly in the randomized trial, where during the first and second years, respectively, adenoidectomy subjects had 47% and 37% less time with otitis media than control subjects and 28% and 35% fewer suppurative (acute) episodes than control subjects. We conclude that adenoidectomy is warranted on an individualized basis for children who develop recurrent otitis media after extrusion of tympanostomy tubes.