In this prospective follow-up investigation, we examined the efficacy of a modified Politzer device in the home treatment of persistent middle ear effusion (MEE) and associated hearing loss in children who had previously participated in a similar clinical trial. Our study group was made up of 38 patients who had been either (1) untreated control participants in the previous study whose hearing in one or both ears had not returned to normal within 11 weeks of their initial audiologic pretest ("former control group"; n = 30), or (2) active-treatment participants in the previous study whose hearing sensitivity in at least one ear had not improved to within normal limits after treatment and who elected to undergo a continuation of treatment ("extended-treatment group"; n = 8). Treatment efficacy was determined by comparing differences in pre- and posttreatment air-conduction thresholds and otoscopic findings. Following treatment, the former control group experienced significant improvements in hearing sensitivity at all frequencies; at the posttreatment test, hearing sensitivity was within normal limits in 43 of 60 ears (71.7%), and normal or moderate tympanic membrane mobility was observed in 30 of 34 otoscopically examined ears (88.2%). In the extended-treatment group, hearing sensitivity returned to within normal limits in 9 of 10 impaired ears (90.0%). These findings further substantiate the efficacy of our modified Politzer device in improving middle ear function and hearing sensitivity in children with MEE, and they support the reliability of the findings reported in our previous study. These results also indicate that many patients in whom initial treatment is not successful may benefit from extended treatment.