Although magnesium sulfate has been a traditional or standard treatment for severe preeclampsia and eclampsia to prevent convulsions, its efficiency has always been in doubt and its induced side-effects also make it controversial for use. In this study, 64 patients, diagnosed with severe preeclampsia, were randomized into group I (34 patients) managed with MgS04, and group II (30 patients) managed without MgS04. There were no occurrences of eclampsia in either group. Although there was no statistical significance in the final delivery method, group I had a higher rate in cesarean section, in which most were significantly due to fetal distress (p<0.05). Furthermore, group I had significantly more babies with poor apgar score than group II (p = 0.019). During the reatment period for those with a gestational age of less than 34 weeks, there were two patients with abruptio placentae in group 1 and the treatment periods were noted to be longer in group II than in group I. From the results of monitoring serum magnesium level in group I, when therapeutic level was achieved, magnesium sulfate induced great discomfort which might have led to the deterioration of the patients' condition. According to this study, magnesium sulfate's minimal efficiency. and its adverse side-effects, also make magnesium sulfate a poor choice in the management of preeclampsia. Therefore, because of our poor understanding of the etiology of preeclampsia, suitable management should be undertaken without magnesium sulfate. Improvement of the patient's pathophysiological condition or termination of pregnancy as early as possible, is recommended.