Abstract: Dichlorvos a synthetic organophosphate poisons are the property of insecticide. These toxins as insecticides in agriculture and medicine for animals and the destruction of ectoparasites can be used. Studies have shown that Dichlorvos creation seizure effects in different animals. Diltiazem, calcium channel blockers, widely used for treatment of cardiovascular diseases. Studies have shown that the calcium channel blockers are anti-convulsant effects in different animal models. The aim of this study was to determine the effect of Diltiazem on Dichlorvos-induced seizures in mice. In this experiment, the animals were received different doses of Diltiazem (2.5, 5, 10, 20 and 40 mg kg^-1) intraperitoneally 30 min before intraperitoneal injection of Dichlorvos (50 mg kg^-1). After Dichlorvos injection, clonic and tonic seizures and death was investigated. Results showed that Diltiazem dose dependently reduced the severity of Dichlorvos-induced seizures so that Diltiazem dose 10 and 40 mg kg^-1, respectively the lowest (p<0.05) and highest (p<0.01) had anti-convulsant effects. The anti-convulsant activity of Diltiazem suggests that possibly due to antagonistic effect on voltage-dependent calcium channel.