Ischemic stroke remains a major cause of mortality and long-term disability worldwide. Effective early management is essential to prevent further neurological damage and support recovery. Hypoxia, particularly during the acute phase, is often underestimated, despite the brain's heightened vulnerability to oxygen deprivation. Monitoring arterial oxygen saturation (SaO₂) is therefore critical. This study examined the impact of desaturation events within the first 24 h of hospital admission using non-invasive pulse oximetry. Data were analyzed from a cohort of 556 patients diagnosed with acute ischemic stroke or transient ischemic attack (TIA) within 7 days of symptom onset, between November 2024 and March 2025. Of these, 323 patients admitted to the stroke unit during the first night of hospitalization were included. SaO₂ levels of 96–97% were associated with more favorable functional outcomes, while desaturation episodes (SaO₂ < 93%) correlated with higher rates of severe complications and a greater frequency of wake-up stroke (WUS). Continuous monitoring was performed using a portable pulse oximeter, which recorded oxygen saturation and heart rate. The device was set to alarm when SpO₂ dropped below a predefined threshold or when heart rate increased by more than 6 beats per minute for at least 8 s. Pulse oximetry proved to be a sensitive and practical method for identifying hypoxia and high-risk patients. These findings support the integration of continuous pulse oximetry into standard stroke care, offering opportunities for timely intervention and improved patient outcomes.