Epilepsy is one of the most common neurological disorders, and topiramate (TPM) is one of the most effective drugs that can render patients seizure-free. The focus of the present study was to evaluate the immunological safety of TPM in a mouse model. We examined the in vitro effect of TPM on immune functions of BV2 microglial cells, RAW 264.7 macrophages, B cells, T cells, and dendritic cells. We also examined the in vivo effect of TPM on mouse immune organs, such as lymph node, spleen, and thymus. When cells were directly treated with TPM at concentrations from 1 to $30{mu}g/ml$, TPM did not affect nitrite production by BV2 cells and macrophages, proliferation of B cells and T cells, or maturation of dendritic cells. In addition, TPM did not change the weight and cellularity of lymph nodes, spleen, and thymus in vivo at doses from 3 to 100 mg/kg injected i.p. into mice once a day for 4 consecutive days. These data showed that TPM, which is widely used as an anti-epileptic drug, is immunologically safe.