Podoplanin (Aggrus), which is a type I transmembrane sialomucin-like glycoprotein, is highly expressed in malignant pleural mesothelioma (MPM). We previously reported the generation of a rat anti-human podoplanin antibody, NZ-1. However, the direct anti-tumor activity against MPM has not been investigated. In the present study, we examined whether anti-podoplanin antibody NZ-1 showed antitumor effects mediated by antibody-dependent cellular cytotoxicity (ADCC). We used human MPM cell lines and tissues. Expression of podoplanin was examined by using flow cytometry and immunohistochemistry. ADCC activity was measured by 51Cr-release assay. In vivo antitumor effects was examined in a xenograft model of human MPM cells in SCID mice. MPM cell lines in 12/15 (80%) expressed podoplanin and MPM tissues also expressed high level of podoplanin. NZ-1 showed high ADCC activity when rat NK cells were used as effector cells. Administration of NZ-1 with rat NK cells significantly suppressed the growth of human MPM cells expressing podoplanin. These results suggest that podoplanin is a promising target for immunotherapy of mesothelioma with anti-podoplanin antibody having ADCC activity.