Background: This study was designed to evaluate the extent of restenosis that occurs after an endoscopic frontal sinus drainage Draf type III (Draf III; modified Lothrop procedure) using a modified technique with reconstruction of the frontal sinus drainage pathway with mucosal transplants, in combination with occlusive postoperative care. Methods: Retrospective case series was performed with 24 consecutive patients undergoing Draf III drainage between 2005 and 2010 using the modified technique of covering the bare bone with mucosal transplants from the nasal septum. To ensure optimal moist wound healing, occlusion of the nose was realized by taping the nose for 2 weeks postoperatively. Frontal ostium measurements were done intraoperatively and at follow-up visits for a minimum of 12 months. Data on patient history, demographics, comorbidities, and computed tomography scans were collected. Results: Mean follow-up was 25.6 months. Eight patients were lost to follow-up. Ninety-four percent of frontal sinus neo-ostia remained open. One patient needed revision surgery using an osteoplastic flap with obliteration. The frontal neo-ostium narrowed by an average of 36.9% from 20.5 x 12.5 to 15 x 9.6 mm. On average, three visits were needed for postoperative care. The patients did not experience significant pain throughout the postoperative healing time. Conclusion: The modified Lothrop procedure is a well-established technique in endoscopic sinus surgery to handle difficult frontal sinus drainage pathways or revision surgeries. The modified technique provides good results in combination with minimized postoperative care and morbidity. A comparative study would be necessary to show superiority to the standard method of Draf III.