The clinical entity of Underactive bladder (UAB) and its urodynamic equivalent Detrusor underactivity (DU) has gained increasing scientific and clinical interest lately as it became obvious that a substantial number of female or male patients suffer of this bladder condition. However, no consensus on the diagnosis or evaluation approach has been reached. The speakers will present and discuss the latest information and key facts concerning UAB/DU. How do we define the LUTS patients with UAB/DU and what are differences in assessment of male and female patients? Which are invasive or non-invasive tools to assess contractility? How can we differentiate detrusor underactivity from bladder outlet obstruction? How to manage our patients?