We report a case of urothelial carcinoma with malignant pleural effusion. A-70-year-old man admitted for dyspnea was found in pleural effusion cytology to have single atypical cells and small clusters with a high N/C ratio. Tumor cells had almost centered nuclei, and some cells showed vacuolar cytoplasm and eccentric nuclei. Tumor cells from urine showed papillary clusters similar to pleural effusion tumor cells. Histologically, the right bladder wall was diagnosed as urothelial carcinoma grade 3 (ulcerated) with lymphatics involvement.