Digital subtraction radiography (DRS) was utilized to evaluate the anatomy and function of the bladder and urethra. Images were obtained in 30 patients, following urography or retrograde cystography, with full bladder distention and during different phases of micturition. The technique permits good demonstration of several anatomical and functional parameters (lowering of bladder base; dynamic origin of trigonal canal; rotation of the urethra; bladder wall motion).