History and Objectives: Trophoblastic pregnancy is one of the high risk pregnancies which considering its frequency and importance and its side effects if it is not diagnosed, requires extensive investigation. The present study is carried out in order to determine epidemiology of trophoblastic pregnancy in Dr. Shaheed Beheshti hospital of Tehran in 1995-1998.

Materials and Methods: A descriptive study is carried out on trophoblastic patients. Diagnosis was based on bHCG, sonography and pathological findings. Patient’s data pertaining to age, number of pregnancies, clinical signs, laboratory data, radiologic and pathologic findings, type of disease and treatment were recorded. Statistical analysis was performed on information gathered.

Results: 48 patients were in 28±8.5 group, with 20-25 age interval. 30 patients (62.5%) had mole pregnancy and 18 cases (37.5%) had trophoblastic tumor pregnancy. 93% of mole pregnancies were considered high risk.

Conclusion: Large number of patients were high risk (93%) and it seems resistance to therapy compared to other groups. Therefore, further studies are required to determine the etiologic and epidemiology and treatment of the disease.