A 71-year-old man was referred to us with a right renal mass that was discovered by computed tomography (CT) examination for acquired hemophilia and leukemoid reaction. He presented with persistent low-grade fever and purpura on the lower legs caused by acquired hemophilia. Contrastenhanced CT scan showed a right renal tumor 6.0×7.4 cm in diameterwith inhomogeneous enhancement. The result of his urine cytology was negative. After improvement of his coagulation by treatment with immunosuppressants and steroids, he underwent open nephrectomy. Histology of renal tissue revealed urothelial carcinoma (G3, pT4, N1). After surgery, his complete blood counts and coagulation improved without administration of immunosuppressants and steroids. Therefore, he was diagnosed with renal pelvic cancer with acquired hemophilia and leukemoid reaction.