Objectives: Controlling the complications of anesthetics (e.g., succinylcholine) seems necessary since they are greater for nulliparous women who undergo elective cesarean section (C-section). The present study aimed to investigate the effects of magnesium sulfate on the complications of succinylcholine administration in nulliparous women undergoing elective C-section. Materials and Methods: This double-blind clinical trial was conducted on 60 nulliparous women during 2012-2013. The women were randomly assigned to A and B groups. Before inducing the rapid anesthesia with succinylcholine, patients in the intervention group received 30 mg/kg of magnesium sulfate within 10 minutes and then the hemodynamic status and the side effects of succinylcholine were recorded in a special form. Statistical tests were performed using repeated-measures ANOVA, chi-square test, and one-way ANOVA tests and the level of significance was determined to be P<0.05. Results: There was no significant difference between the two groups in terms of demographic data (P>0.059). However, the results indicated that there was a significant difference between the 2 groups regarding the myoglobin level (P=0.010). Contrarily, the results showed that most patients in the intervention (n=23) and control (n=15) groups experienced no or mild and severe fasciculation, respectively (P<0.001). Conclusions: In general, magnesium sulfate can greatly control and reduce the complications of succinylcholine administration, including fasciculation.