For the patients who visit outpatient clinics due to asymptomatic microscopic hematuria, cystoscopy has been looked upon as rather invasive compared to other diagnostic methods. We tried to elucidate the actual diagnostic value of cystoscopy in the initial evaluation of asymptomatic microscopic hematuria. We reviewed the results of cystoscopic examinations in 213 patients who visited our hospital due to asymptomatic microscopic hematuria. No definite lesion that could explain the microscopic hematuria was detected by means of IVP, urine cytology, and other nephrologic evaluations for all the patients. Among the abnormal cystoscopic findings in 55 patients, the lesions suspected to be directly related to microscopic hematuria were classified as 'significant lesions' (31 patients, 17.6%) which include entities such as bladder cancer (1.31%). 27 of 31 patients with significant lesions (85.2%) were over 50 yr old, and furthermore, 3 patients who were diagnosed as bladder tumor by cystoscopy were over 60 yr. Cystoscopy should be utilized as initial diagnostic modality in lder patients with asymptomatic microscopic hematuria to rule out any possibility of bladder cancer occurrence. Further studies are needed to justify implementation of cystoscopy as an initial diagnostic modality in younger patients with asymptomatic microscopic hematuria.