Background and Objectives: Febrile convulsion is one of the most common types of seizure in childhood. Its pathogenesis is unknown, so studying its cause is valuable. The purpose of this study was to determine the serum level of zinc and magnesium in children withfebrileconvulsion (F.C) (3 months to 6 years age). Patients and Methods: In this analytical case-control study, serum level of zinc and magnesium in 60 children with F.C in Shahid Beheshty Hospital of Kashan, center of Iran, was determined. The control group was composed of febrile children with no seizure. All children in both groups were 3 months to 6 yr of age and had not any background of disorders. Serum level of zinc & magnesium was determined by biochemical methods in all groups. Finally, the data were analyzed by SPSS and t test. Results: The mean serum level of zinc and magnesium in case group, was lower than that of zinc & magnesium in control group (P<0.05). There was no relationship between sex, type and time of seizure with serum level of zinc or magnesium in children in case group. Conclusion: There was a relationship between serum level of zinc & magnesium and the presence of F.C in children. So, it is suggested to use supplements of zinc and magnesium in diet of affected children for prophylaxis of febrile seizure recurrences.