Introduction: This prospective randomized case-control study was performed to compare the surgical outcomes of our swing-door overlay tympanoplasty with or without absorbable gelatine sponge (AGS, gelfoam) packing in the middle ear cavity, according to the surgical procedure. Subjects and Methods: Fifty-seven patients who underwent swing-door overlay tympanoplasty by a single surgeon were enrolled in the study. The data of 30 patients of the gelfoam-packing group (GPG) and 27 patients of the non-gelfoam-packing group (NGPG) were prospectively collected and compared. Results: Closure of the tympanic membrane was found to be successful in all patients at postoperative 3 months evaluation. NGPG showed a statistically better healing process compared to GPG; earlier epithelialization and less fascia edema in NGPG than in GPG (P<0.05). The air-bone gap (ABG) measured at postoperative 1 and 2 months was smaller in NGPG than GPG, although there were no statistical differences. Conclusion: Swing-door overlay tympanoplasty showed good surgical outcomes in terms of graft uptake rate regardless of AGS packing. However, this study revealed earlier healing process and faster recovery of ABG in NGPG, thereby indicating that the gelfoam in the middle ear may interfere with both hearing recovery and the healing process of neodrum. Non-gelfoam packing in the middle ear cavity appeared to be superior to gelfoam packing in swing-door overlay tympanoplasty.