Aims: To evaluate sclerotomy closure after 25- and 23-gauge transconjunctival sutureless pars plana vitrectomy using optical coherence tomography (OCT). Methods: Forty-eight eyes (20 with a macular hole and 28 with an epiretinal membrane) of 47 patients (mean age, 66.5 years) who underwent one of the two procedures were included. Three sclerotomy sites in each eye were measured by cross-sectional OCT images vertical and parallel to the limbus on weeks 1 and 2 and months 1, 2 and 3 postoperatively. Results: After 25-gauge vitrectomy, the scleral wounds evaluated by OCT closed in 40.6% of the eyes at 1 week, 53.3% at 2 weeks, 60.5% at 1 month, 63.6% at 2 months and 63.9% at 3 months. There were significant differences in the closure rates between 1 week and 1 month (p = 0.015), 2 months (p = 0.007) and 3 months (p = 0.006) postoperatively. After 23-gauge vitrectomy, the scleral wounds closed in 31.6% of the eyes at 1 week, 50.0% at 2 weeks, 57.4% at 1 month, 63.0% at 2 months, and 61.1% at 3 months postoperatively. There were significant differences in the closure rates between 1 week and 1 month (p = 0.011), 2 months (p = 0.001) and 3 months (p = 0.002) postoperatively. The wound closure rates did not differ significantly between the two procedures. Conclusions: Scleral wounds after 25- and 23-gauge transconjunctival sutureless pars plana vitrectomy can be evaluated with OCT. Wound healing seems to be complete 2 weeks postoperatively.