OBJECTIVE To describe a new technique of virtual cystoscopy (VC, used previously but with catheterization to drain residual urine and insufflation with air or carbon dioxide) with no invasive catheterization, used in parallel with intravenous urography (IVU), as conventional cystoscopy is an invasive but essential examination, and VC with multislice computed tomography (CT) was introduced to make preliminary examinations noninvasive. PATIENTS AND METHODS Using multislice CT and a device with 16 rows of detectors, we examined five patients using VC that previously involved catheterization, termed 'air VC' and 16 using VC with the new technique, termed 'IVU VC' We assessed the new technique by evaluating the tumour detection rate, and merits and demerits of both types of VC. RESULTS The detection rate of bladder tumours by IVU VC was similar to that from air VC; moreover, IVU VC overcame two significant disadvantages of air VC, i.e. the appearance of the water surface and the need for catheterization. CONCLUSION Conventional cystoscopy is still an essential examination but this new method of IVU VC may be ideal for preliminary examination of the bladder.