The case of tremendous salpinx hematoma coexisting with a residual uterus horn has been described. A menstrual blood from the little cavity of residual horn filled progressively the salpinx, which had abdominal ostium closed. A congenital malformation, in consequence of Muller tubes defective development, has been a direct cause of the disease. The ethology of the malformation has not been found. Primary diagnosis suggested an ovarian cyst or a malignant tumour. Neither physical examination nor USG made the diagnosis easier. The case has showed, how difficult the recognition of pelvic tumours in young women is. Sonography may be very helpful in diagnosing of such malformations but in early stages only.