In a previous trial involving 109 children with chronic otitis media with effusion of at least a 2 months' duration that had been unresponsive to medical treatment, we compared the efficacy of myringotomy with tube insertion, myringotomy alone and no surgical intervention with regard to time with middle ear effusion, hearing status and other indices over a 3-year period. Because interpretation of the results was rendered difficult by certain complexities of study design, the present trial with a revised protocol was carried out in an additional group of 111 children. As in the previous trial, myringotomy with tube insertion resulted in less time with effusion and better hearing than did either myringotomy alone or no surgery. However, acute and chronic otorrhea and tympanic membrane perforation developed not uncommonly after tube insertion. Myringotomy alone offered no advantage over no surgery regarding the percent of time with effusion or the number of episodes of acute otitis media. Currently for children with long-standing middle ear effusion, we recommend either watchful waiting with periodic hearing assessment or myringotomy with tube insertion, individualizing the recommendation for each child.