Three applications of markers of detection: screening, replacing surveillance cystoscopies, and guiding evaluation of asymptomatic hematuria, are discussed. In one study, repetitive hematuria screening in men age >or=50 effectively shifted the stage of high grade cancers at diagnosis from muscle invasive to earlier ones, reducing bladder cancer, and all cause mortality. This technique is sensitive, but is not terribly specific. Testing other markers alone or in combination with each other and/or hemoglobin screening in similar or higher risk populations is now beginning. Currently, no commercially available marker is sufficiently sensitive to replace all surveillance cystoscopies for low risk bladder cancer, although some cystoscopic examinations can probably be replaced by markers. Available markers are too insensitive for small, high grade cancers to replace any surveillance cystoscopies in this group. No single marker or combination of markers can safely replace cystoscopy in the work-up of patients with microhematuria who are at high risk for harboring bladder cancer. However, markers may be useful for directing which patients age <or=40 with asymptomatic microhematuria without histories of smoking, particularly women, require cystoscopic evaluation.