Aim: A comparative study between Nifedipine and magnesium sulfate for treatment of preterm labor. Methods: Eligible women with preterm labor between 24-37 week gestations were selected for the study. Nulliparous and multiparous pregnancies with intact membranes, showing clinical signs of preterm labor were included in this study. The diagnosis of preterm labor is based on the presence of 4 uterine contractions or more over 30 minutes, each lasting at least 30 seconds, and documented cervical change (dilatation of 0-4 cm and effacement of at least 50%). Results: 5 patients (5%) after 24 hours, 9 patients (9%) after 48 hours, 7 patients (7%) after 72 hours and 54 patients (54%) after 7 days had delivery in the nifedipine group and 11 patients (11%) after 24 hours, 5 patients (5%) after 48 hours, 5 patients (5%) after 72 hours and 62 patients (62%) after 7 days had delivery in the magnesium sulfate group. This characteristic was not statistically different between the two groups. In this study, 28 patients (28%) in nifedipine group and 14 patient (14%) in magnesium sulfate group had a failure treatment (contractions did not subside) and needed to take other tocolytic medications. This characteristic was also not statistically different between the two groups. Conclusion: we concluded that the oral nifedipine is a suitable alternative for magnesium sulfate with the same efficacy and side effects in the management of preterm labor.