The purpose of the present study was to evaluate the efficacy of a single dose of botulinum toxin (BTX) at the Yonsei point for the treatment of gummy smile (GS). A total number of 45 female patients were enrolled in the study at a private clinic over a period of 24 months. Three units of onabotulinumtoxinA (BTX-A) per site (90 hemifacies) were initially injected at the Yonsei point. The patients were then assessed at 2, 12, 24, and 36 weeks postinjection. The data were evaluated using mean standard deviation, analysis of variance (ANOVA), and Tukey's post hoc test. The results of the study revealed that a single dose of BTX-A injected at the Yonsei point was effective in the treatment of GS (P 0.05) and achieved better results than multiple injections at various sites.