The visualization of the level and pattern of apnea and hypopnea events is of pivotal importance in the diagnosis and therapeutic decision-making for sleep-disordered breathing (SDB). There are numerous techniques available to assess upper airway obstruction, which include imaging, acoustic analysis, pressure transducer recording, and endoscopic evaluation. Drug-induced sleep endoscopy (DISE) is a diagnostic tool that allows the dynamic, three-dimensional evaluation of the patterns of vibration and collapse of the upper airway of SDB patients. DISE may change the initial surgical planning in a high percentage of cases. A universally accepted and methodologically standardized DISE could provide significant insight into its role to improve surgical outcomes. However, up to now the ideal DISE protocol remains an open question.