Vaginal malignant germ cell tumors (MGCTs), predominantly yolk sac tumors, are extremely rare, with no established consensus on optimal management. This study evaluated whether post-chemotherapy surgery is necessary for vaginal MGCTs. A retrospective analysis was conducted on patients diagnosed with vaginal MGCTs from 1996 to 2023. Progression-free survival (PFS), overall survival (OS), the impact of surgical intervention, and the presence of post-chemotherapy residual mass (RM) were assessed. Seventy-five patients (median age:11 months) were included. Six underwent initial tumor resection, and all received platinum-based chemotherapy. RM was detected post-chemotherapy in 57% of evaluable cases (40/70), with vaginoscopy outperforming standard imaging in detection (p < 0.001). The 5-year PFS and OS rates were 83% (95%CI: 71-90) and 94% (95%CI: 84-98), respectively. Neither RM (p = 0.64) nor delayed surgical intervention (5-year PFS: 77% (95%CI: 54-90) without surgery versus 85% (95%CI: 70-92) with surgery; log-rank test p = 0.72) significantly impacted PFS. Neoadjuvant platinum-based chemotherapy yields excellent survival outcomes in vaginal MGCTs. Vaginoscopy appears more sensitive than standard imaging for RM detection and is recommended for post-chemotherapy evaluation. In the absence of RM on vaginoscopy and with negative tumor markers, systematic post-chemotherapy surgery may be unnecessary. A global consensual framework for managing is proposed.