Information regarding the design and usage of inferiorly based nasolabial flap for lower lip and commissural defect reconstruction following ablative cancer surgery remains limited. This study aimed to provide our design and experiences for such reconstructive purpose. Patients with lower lip or oral commissural cancer who received curative surgery involving reconstruction with inferiorly based nasolabial flap were included. The demographic data and clinical outcomes of these patients were obtained by retrospective chart review. A total of eight patients were enrolled in this study. All patients received ablative surgery at the National Cheng Kung University Hospital during May 2019 to May 2021, with their surgical defects reconstructed with unilateral inferiorly based nasolabial flap successfully. Among the five patients with lower lip cancer, one had a limited area of necrosis at flap tip. Another patient had a small orocutaneous fistula that healed spontaneously. No trismus or oral incompetence was noted following recovery. For the three patients with commissural cancer, a second stage commisuroplasy was needed after primary reconstruction. One patient had limited wound dehiscence at mouth angle following surgery, resulting in mild oral incompetence. Although mild trismus was noted in these three commissural cancer patients, all patients resumed normal diet during follow-up. Inferiorly based nasolabial flap is an excellent local flap for lower lip reconstruction following cancer ablative surgery. It is also a viable option for reconstruction of oral commissural defects. Minimal donor side morbidity, good functional recovery, and esthetic outcomes can be achieved with meticulous flap design.