Background. Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) presents a multiethiological congenital abnormality of Müllerian’s ducts and it is characterized by: agenesia of the 2/3 superior part of vagina and uterine anomaly, functional and normally developed ovaries and fallopian tubes and normal secondary sexual characteristics and female karyotype. Ovarian tumors in case of this syndrome are very rare, being described in literature as unique clinical cases. Case report. Case #1: A 35 y.o. woman with MRKH syndrome was admitted to institute with lower abdominal pain and deep dyspareunia. Her previous gynecological history included the creation of a peritoneal neovagina (Davydov’s procedure) 10 years earlier. Exploration of the abdomen: a huge (20x15x10.5 cm), solid and lobular tumor of the left ovary; the band-like uterus and a normal right ovary. Laboratory studies revealed an elevated CA 125 (127 U/ml) and β-hCG (53 mIU/ml). Resection of the mass, bilateral salpingo-oophorectomy, and omentectomy were performed. Microscopic examination of surgical specimen confirmed the diagnosis of dysgerminoma. The postoperative recovery was uneventful and four courses of chemotherapy were performed. Case #2: A 38 y.o woman with history of MRKH syndrome and Davydov’s procedure 17 years earlier, was admitted to hospital with constant lower abdominal pain for 4 months. Gynecological examination: neovagina with a good anatomical result (length 7 cm) and an elastic, painful mass in the projection of left annexes. At CT: a 107x87x93 mm cystic tumor. Laboratory studies revealed a normally CA 125 and b-hCG levels. A laparoscopic removal of tumor and left annexes was performed. Exploration showed a cystic mass on the left ovary, and left ovariectomy was performed. Microscopic examination of surgical specimen confirmed the diagnosis of Sertoli-Leydig cell tumor. The postoperative recovery was uneventful and she continued the treatment at oncological department. Case #3: A 14 y.o patient was admitted to the surgery department with hypogastric pain, increased abdominal volume and primary amenorrhea. At MRI: a solid mass in the pelvic cavity with intraabdominal spread with dimensions 115.3×75.2×82mm. A diagnostic laparoscopy was performed and determined the lack of the uterus (two uterine rudiments), the left ovarian tumor and follicular cyst (5×5 cm) on the right site. Conversion with bilateral ovariectomy was performed. The light microscopy data and the immunohistochemical profile revealed ovarian dysgerminoma. The postoperative period was without any particularities. Further the patient followed six chemotherapy courses Conclusions. Ovarian tumors in MRKH syndrome refer to a very rare gynecological pathology and should be considered in the differential diagnosis of abdominal cavity volume formations in case of this malformation. Long term clinical and radiological monitoring of patients with MRKH syndrome should be considered justified.