Introduction: Advanced lip carcinomas can invade adjacent structures. Performing surgery for these cancers will lead to defects in this anatomically and functionally important area and will cause post-op difficulties such as drooling, speech alterations and aesthetic considerations, if not properly managed. Case Report: In this study, we will introduce a radial forearm free flap with palmaris longus tendon to reconstruct a defect of a large lower lip carcinoma. Our patients was a male in the 7th decade of life with an advanced lower lip carcinoma invading the full thickness of the buccal mucosa, left commissure and the left third of the upper lip. Resection was performed with adequate margins; checked by frozen sections and radical modified neck dissection was also performed on the left side. Free radial forearm flap with palmaris longus tendon was harvested and anastomosed in the neck. Four months after surgery commissurroplasty was done and the flap volume reduced Conclusion: The radial forearm free flap with palmaris longus tendon provides a good functional lip with a reasonable aesthetics in our patient. The patient was satisfied with the result and there were no functional complaints such as drooling reported by him. We think that this flap could be a flap of choice for reconstruction of the large, full thickness lip defects
