BACKGROUND: This study aimed to determine red blood cell (RBC) and serum folate and vitamin B12 levels as well as their intake in schizophrenic patients. METHODS: The folate and cobalamin status of 60 schizophrenic patients (15-55 years) was compared to 60 matched healthy controls using Radio Isotope Dilution Assay (RIDA). RESULTS: Serum and RBC folate in schizophrenic patients was significantly lower than the control group. Mean serum cobalamin levels in the schizophrenic group were higher than controls. CONCLUSIONS: This study showed that folate deficiency is common in schizophrenic patients; therefore, it is important to pay attention to folate levels in these patients.