Peroxisome proliferator activator-receptor (PPAR)-γ is a ligand-activated transcriptional factor belonging to a steroid receptor superfamily. PPAR-γ plays a role in both adipocyte differentiation and carcinogenesis. Up-date, PPAR-γ is expressed in various cancer tissues, and PPAR-γ ligand induces growth arrest of these cancer cells. In this study, we examined the expression of PPAR-γ in human urological cancer (including renal cell carcinoma, bladder tumor, prostate cancer and testicular cancer) by RT-PCR and immunohistochemistry, and we also examined the effect of PPAR-γ ligand in these cells by MTT assay, flow cytometry and hoechest staining. PPAR-γ expression was significantly more extensive and intense in malignant tissues than in normal tissues. PPAR-γ ligand induced the reduction of malignant cell viability through early apoptosis. These results demonstrated that generated PPAR-γ in urological cancer cells may play an important role in carcinogensis and become a new target therapy in the treatment of urological cancer.