Surgery is often necessary after failure of conservative therapy for urinary incontinence. Guidelines recommend urodynamic studies before surgery. A distinction is made between non-invasive (uroflowmetry) and invasive methods (cystometry and pressure-flow study, if necessary as combined videourodynamics, as well as urethral pressure profile). All examinations serve to objectify and quantify the symptoms, to correctly assign symptoms to the pathophysiology and anatomy as well as to identify risk factors, which often have a significant influence on the success of surgical therapy. Given appropriate experience, complications and often significant sequelae of bladder dysfunction affecting the patient's quality of life and life expectancy can be recognized. Urodynamic studies are performed to help narrow down potential diagnoses, to develop therapeutic strategies, and to obtain prognostic parameters. The following article is intended to provide some support.