Objective. High-dose-rate (HDR) brachytherapy using a customized mold is a minimally invasive treatment for oral cancer; however, it is difficult to use this technique for buccal and lip cancers involving the commissura labiorum, owing to its anatomic form. The purpose of this study was to introduce an improved customized mold consisting of 2 pieces to allow the fixation of molds to these sites.Study design. Five patients with buccal carcinoma and 1 patient with lip carcinoma were treated with this technique after external beam radiotherapy. One patient with neck metastasis underwent both neck dissection and partial tumor resection before HDR brachytherapy.Results. At the end of the follow-up period, 5 patients had no tumor recurrence, and 1 patient had suffered local recurrence.Conclusions. Our technique is a viable therapeutic option for patients with buccal and lip carcinomas for whom the therapeutic modalities are limited by age, performance status, and other factors. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:118-125)