Introduction:Acorus calamus is being used in Ayurveda as Medhya Rasayana to enhance mental ability and used in treatment of various brain related disorders. Objective: Extraction of volatile oil from Acorus calamus rhizomes and Isolation of β–Asarone from it and anticonvulsant activity of volatile oil in mice using MES and PTZ models. Method: The volatile (calamus) oil was extracted using hydro steam distillation. Calamus oil was subjected to column chromatography using Silica gel in glass column for isolation of β-Asarone. Calamus oil was evaluated for anticonvulsant activity at 30, 100 and 300mg/kg dose using MES, scPTZ, minimum clonic seizure (at 6 Hz.) model and Rotarod test was used to determine the neurotoxicity of volatile oil. Results:β-Asarone was isolated and confirmed by structure elucidation using 1H-NMR, 13C-NMR, IRS, UVS and Mass spectroscopy. Calamus oil was found to be inactive in preliminary screening at all dose levels but has shown neurotoxicity at 300 mg/kg. Although, volatile oil was found to be active in minimal clonic seizure test at 6 Hz. At 100 mg/kg, it displayed protection even up to 4.0hr indicating longer duration of action. ED50 (48.13 mg/kg) and TD50 (224.13 mg/kg) of volatile oil at 6 Hz in mice also determined at 95% C.I. Protective index(PI) value of volatile oil was found to be 4.65. The experimental results were compared with the standard drug Phenytoin (30 mg/kg). Conclusion: The calamus oil has shown a protective index that can be compared with Phenytoin and can be used as an alternate of synthetic antiepileptic drugs.