Primary vaginal endodermal sinus tumor (EST) in newborns and children treated in a tertiary centre: clinical characteristics, management, and long-term prognosis. A hospital performed a retrospective evaluation and analysis of the clinical data of individuals who had pathologically diagnosed primary vaginal EST between January 1997 and December 2017. About 21 patients met the inclusion criteria and were analyzed. Diagnosis occurred on average at 11 months (range, 4–44 months). Abnormal vaginal bleeding and a polypoid mass outside the vagina were the most often reported symptoms. Serum alpha-fetoprotein (AFP) levels returned to normal after 2–4 cycles of chemotherapy with the PEB (cisplatin, etoposide, bleomycin) regimen (median, 2 cycles). About 20 patients (95.2% of the total) achieved complete remission after 3-13 cycles of chemotherapy. The median number of cycles required to achieve this result was 5. About 80 months was the midpoint of the follow-up period (range, 4-281 months). About 19 patients were found to be alive and disease-free at the time of the most recent checkup, for a 90.5% survival rate. Rare malignant germ cell tumors found in the vaginal area, such as EST, responded well to treatment. Surgery that is minimally invasive, followed by chemotherapy with PEB, is an efficient treatment. Response to treatment and recurrence.