Urodynamics encompass a number of functional tests of the lower and occasionally the upper urinary tract. These tests comprise uroflowmetry, cystometry or measurement of bladder pression during bladder filling and voiding, urethral pressure profile, electromyography (EMG) of the external urethral sphincter, pressure-flow studies and video-urodynamics. Alone or in combination these examinations have become essential elements of urological clinical work-up, since they do not only allow to precisely classify a functional disorder but also to establish an adequate therapy. Urodynamics are nowadays standard in any urological department.