Summary Aim: The pregnancy course in women with gestational ovarian mass and conservative or operative management. Material and methods: In retrospective analysis we analyzed 83 pregnant women with ovarian mass diagnosed between 2002-2009. We considered the following factors: gestational age when diagnosed, ultrasound picture, clinical symptoms, level of CA 125, treatment used, pathologic results and pregnancy outcome. Results: In this group of patients 29 (35%) underwent surgery and 54 (65%) were managed conservatively. In 83% of operated women ovarian mass was diagnosed before 11 gestational week. Only 27,5% of patients had pain. CA 125 level was elevated in 48,3% women. In all operated patients laparotomy was performed. The most common pathologic finding was mature teratoma (37,9%) and serous cyst (34,5%). In only one patient we diagnosed borderline serous carcinoma in both ovaries. Among operated patients, 86% delivered at term healthy newborns. In conservatively managed group level of CA 125 remain within a normal range. Patients were symptoms free and pregnancy course was uneventful. In 85% non operated women within 6 postpartum weeks ovarian masses disappeared. Conclusion: According to our analysis adequate ultrasound image interpretation of ovarian’ tumors in pregnancy is of the highest importance in further medical management. Conservative treatment with systematic obstetric care may help to reduce the number of surgical intervention. Surgical treatment of ovarian tumors in pregnancy increases the risk of premature deliveries.