Auricularia polytricha is a popular mushroom found all over the world. This article describes a study of the antiepileptic effect of A. polytricha, a mushroom that is used traditionally for treating asthma, rheumatism, tumors, cough, fever, and epilepsy, and for its antimicrobial effect. We carried out toxicity studies to identify a standard dose of A. polytricha aqueous extract; maximal electroshock (MES)- and isoniazid (INH)-induced seizures in albino mice were used to screen for the extract's antiepileptic activity. Per Organisation for Economic Co-operation and Development Guideline 423, up to 2000 mg/kg body weight of extract was toxic. Animals were treated with aqueous extract at doses of 200, 400, and 600 mg/kg body weight. Phenytoin was used as the reference anticonvulsant drug for comparison. The investigation found a significant interruption in INH-induced clonic seizure. During MES, we found a reduction in the period of hind leg extensor phase; mice exhibited a significant decrease in the duration of hind limb extension after being treated with 400 and 600 mg/kg doses of A. polytricha. Comparable results were obtained in the INH group, as the extract seemed to delay the onset of a clonic seizure. The aqueous extract of A. polytricha showed antiepileptic action against MES- and INH-induced epilepsy in the mice. This extract, however, requires additional study in order to completely explain its active ingredients and their mechanisms of action.