Isaacs syndrome is a disease characterized by nerve hyperexcitability and pseudomyotonia and treated with immunomodulatory and symptomatic therapy approaches. Here, we report a case of anti-(leucine-rich glioma-inactivated 1) antibody-positive patient diagnosed as Isaacs syndrome and accomplished a nearly complete response to only four sessions of therapeutic plasma exchange (TPE). Our experience suggests that TPE along with other immunomodulatory agents may be beneficial and well-tolerated approach in patient with Isaacs syndrome.