Aim: To evaluate whether an acute vulvar ulcer that developed after the COVID-19 vaccine administration is an adverse effect of the vaccine. Methods: This is a descriptive study of two cases that we observed in addition to cases that have been reported in the literature. We searched for case reports in the PubMed. The consistency of clinical manifestations among cases and the association between ulceration and vaccination were assessed. Results: Fourteen female patients were identified, including 12 patients from 8 literatures published in 2021 and 2022 and 2 patients from our cases. Of the 14 patients, 11 had received the BNT162b2 vaccine, 2 had received the ChAdOx1 nCoV-19 vaccine, and one had received the mRNA-1273 vaccine. The patient's ages were 16.9 ± 5.0 (mean ± SD) years. Postvaccination, the disease progressed in the following sequence (time interval from vaccination): fever and other systemic inflammatory reactions (0.9 ± 0.4 days), development of vulvar ulcers (2.4 ± 1.2 days), and resolution of the ulcer (16.9 ± 7.4 days). The ulcers eventually healed in all cases, except one where the prognosis was not noted. For two-dose vaccine recipients, more patients developed the ulcer after the full vaccination (the second or third doses) compared with after the first dose: n = 10 and n = 2, respectively. Conclusion: The acute vulvar ulcer was closely associated with COVID-19 vaccination in terms of temporality and vaccine doses, supporting the notion that a vulvar ulcer is an adverse event of the COVID-19 vaccines.