Background: infertility is defined as one year of unprotected coitus without conception. By artificial reproductive technology, rate of multiple pregnancies is increased to 35%. This leads to an increase in cesarean section rate, prematurity, perinatal mortality.Materials and methods: This study is designed as retrospective descriptive- analytic. All of the pregnant women with twin gestation coming to Taleghani, Mahdieh, and Imam Khomeini hospital during the years 1996-2003 were included in the study sequentially, regardless of age or parity. Excluding criteria was past history of preterm delivery, abortion, hypertension and previous cesarean section. For the data analysis, we used the Z test.Results: we compared 76 spontaneous twin pregnancies with 74 twin pregnancies after IVF and 76 twin pregnancies after ovulation induction, with respect to these parameters: hypertension, birth weight, gestational age, mode of delivery, abortion, premature rupture of membrane, preterm delivery, APGAR score, perinatal mortality. We did not find any significant difference in having hypertension, gestational age at birth, premature rupture of membrane, abortion, preterm delivery, APGAR score, still birth and neonatal death between three groups. Mean maternal age in spontaneous group was 26.5 years old, in IVF group 34 years old and in induction group 30 years old. There were significant numbers of primiparous women in the IVF and in induction group. The cesarean rate was significantly higher in IVF group (Z>1.96) and the vaginal delivery rate was significantly higher in spontaneous twin pregnancy (Z>1.96).Conclusion: There is no difference in perinatal outcomes in 3 groups.