Tosufloxacin tosilate, a member of the naphthyridine group, was developed in Japan and became commercially available in 1990. We experienced a 69-year-old male who developed thrombocytopenic purpura due to tosufloxacin tosilate. The diagnosis was made when similar symptoms (petechiae and thrombocytopenia) were induced by inadvertent challenge with tosufloxacin tosilate. In this paper, we report the first case of tosufloxacin tosilate-induced thrombocytopenic purpura and present a brief published work review.