FGF-like growth factors have been detected in the urine of patients with bladder or renal cell carcinoma. FGF-1-like and FGF-2-like proteins have been detected in the urine of patients with bladder carcinoma. However, the expression of FGFs and their receptor in bladder and renal cell carcinoma cells remains limited. We measured the mRNA levels of FGFs and their receptor in these carcinoma cell lines by means of RT-PCR. We detected FGF-8 mRNA expression in murine cell lines of bladder and renal cell carcinomas but not in those of the normal bladder and kidney. Furthermore, FGF-8 mRNA expression was detected in all human bladder and renal cell carcinoma cell lines tested. We also frequently detected FGF-1, FGF-2 and FGF-5 mRNA expression in human bladder and renal cell carcinoma cell lines. These results indicate that FGF-8 is also candidate for marker of these types of carcinoma as well as FGF-1 and FGF-2.