Silver oxide-impregnated tympanostomy tubes have been shown to decrease the incidence of postoperative otorrhea, but without a significant effect in the first postoperative week.To evaluate prospectively our results with silver oxide-impregnated tympanostomy tubes and to identify factors associated with a higher incidence of early postoperative otorrhea.Prospective nonrandomized study.University referral center.Six hundred thirty patients with chronic otitis media with effusion or recurrent otitis media.Silver oxide-impregnated Silastic tympanostomy tubes were inserted in 1254 ears. Subjects with mucoid or purulent effusions or blood at the myringotomy site at surgery were treated with topical antibiotic prophylaxis (sulfacetamide sodium-prednisolone acetate or neomycin sulfate-polymyxin B sulfate-hydrocortisone) for 5 days after tympanostomy tube placement.Incidence of otorrhea after tympanostomy tube insertion at 1 week and 1, 3, 6, 9, and 12 months after surgery.The overall incidence of postoperative otorrhea was 1.9%. The incidence of otorrhea in the first postoperative week was 5.6%; the incidence of otorrhea after the first postoperative week was 1.2% (P.001). Within the first postoperative week, a significantly greater incidence of otorrhea was noted in patients younger than 3 years (7.8%), in patients with mucoid effusions at surgery (8.6%), and in patients younger than 3 years with mucoid effusions at surgery (15.2%).Silver oxide-impregnated tympanostomy tubes are associated with a low overall incidence of postoperative otorrhea. A significantly higher incidence of otorrhea is seen during the first postoperative week, compared with the incidence after the first week. Patients with thick middle ear effusions and age younger than 3 years have a significantly greater incidence of early otorrhea after tympanostomy tube placement.