Purpose <p>Drug-Induced Sleep Endoscopy (DISE) is increasingly used to evaluate upper airway dynamics in obstructive sleep apnea patients (OSA). It enables real-time visualization of collapse and may support treatment selection; however, its true clinical impact and limitations remain controversial. This study aims to summarize the current evidence regarding the real role of DISE in OSA management.</p> Methods <p>A structured literature review of the literature was conducted, focusing on key aspects of DISE, including its diagnostic utility, comparison with awake endoscopy, pharmacological agents used, effects on sleep architecture and muscle tone, the role of bispectral index, indications and contraindications, relevance in hypoglossal nerve stimulation selection, and its impact on surgical outcomes.</p> Results <p>DISE provides dynamic assessment of upper airway collapse, facilitating anatomical diagnosis and treatment personalization. It is useful in complex cases, treatment failures, and candidate selection for HNS. Commonly used agents -propofol, midazolam, and dexmedetomidine- differ in their effects on sleep architecture and muscle tone, none fully reproducing natural sleep. Importantly, current evidence shows no consistent improvement in surgical outcomes when DISE is used compared with awake evaluation alone. Additionally, variability in protocols and interpretation limits reproducibility.</p> Conclusions <p>DISE is a valuable complementary tool for anatomical localization of upper airway collapse and treatment planning in OSA. However, it cannot replace polysomnography as the diagnostic gold standard and should be interpreted within a comprehensive clinical context. Further standardization and high-quality studies are needed to better define its role and optimize its clinical utility.</p>