There is a need for the development of reliable tumor markers in bladder cancer. A number of studies this past year focused on the evaluation of urinary markers that hold promise as noninvasive adjuncts to traditional diagnostic or surveillance techniques, principally urinary cytology and cystoscopy. Tests for bladder tumor antigen, NMP22, and fibrin degradation products, as well as the Immunocyt test, are commercially available. Other urinary marker tests discussed in this review include telomerase, cytokeratins, and vascular endothelial growth factor, Although these tests in many instances have improved sensitivity in detecting bladder cancer compared with urinary cytology, none have become widely accepted in routine clinical practice. Nonetheless, with further refinement and prospective validation in multicenter trials, markers such as these may provide information that would permit tailoring on an individual basis the type of as well as interval of surveillance examinations. Furthermore, they may also provide information allowing the appropriate selection of therapy based on predicted response. in addition to urinary markers, intense research efforts have also focused on developing clinically useful molecular prognostic markers. A number of cell-cycle regulatory proteins, including p53 and p21, have received much attention in this regard. Emerging data suggests that it may soon be possible to determine the molecular phenotype of both superficial and invasive bladder cancers, thereby providing information regarding tumor behavior on an individual basis. As with urinary markers, however, no molecular markers have been incorporated as yet into day-to-day patient care. Assurances of reproducibility, standardization, and prospective validation studies are urgently needed. It is only through this type of rigorous evaluation that the level of confidence sufficient to base treatment decisions on marker status will be attained. Curr Opin Oncol 2000, 12:255-259 (C) 2000 Lippincott Williams & Wilkins, Inc.