Endotracheal intubation (ETI) is a common procedure performed in critically ill patients in intensive care units but carries the risk of serious complications, particularly hypoxemia. Prolonged intubation duration is associated with a higher risk of oxygen desaturation, emphasizing the importance of evaluating the available evidence. This study aimed to analyze the relationship between endotracheal intubation duration and the risk of hypoxemia through a systematic review. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Literature was identified from the PubMed, Scopus, and Google Scholar databases using keywords related to endotracheal intubation, intubation duration, hypoxemia, and critical care. Nine studies meeting the inclusion and exclusion criteria, including cohort, case-control, and randomized controlled trials, were analyzed. The findings demonstrated that prolonged intubation duration was consistently associated with an increased risk of hypoxemia. Six studies reported that intubation lasting more than three minutes significantly increased oxygen desaturation. Inadequate preoxygenation and poor clinical condition before intubation also contributed to this risk. Conversely, preoxygenation techniques such as Non-Invasive Positive Pressure Ventilation (NIPPV) and High-Flow Nasal Cannula (HFNC), combined with adequate oxygenation monitoring, effectively reduced hypoxemia. Therefore, optimizing preoxygenation strategies and minimizing intubation duration are essential to improve patient safety during endotracheal intubation procedures.