Noninvasive tests for detecting genetic or molecular alterations in urine indicative of urothelial cancer are increasingly becoming the focus of urological cancer research. Since its approval by the US FDA in 2001, the fluorescence in situ hybridization test (Vysis UroVysion) has been widely evaluated. In general, published data demonstrate better sensitivity and equal or better specificity compared with routine cytology, which is still considered the 'gold standard' in diagnosing and monitoring bladder tumors. However, the fluorescence in situ hybridization test seems to provide not only a useful tool in bladder cancer detection, but also in the diagnosis of upper urinary tract tumors, surveillance and determining therapy effectiveness. This multitarget assay that detects four different chromosomal aberrations in tumor cells is a kind of objective molecular cytology and has proven advantages over routinely used cytology.