Obstructive sleep apnea (OSA) is a common sleep disordered breathing in stroke patients. This case report aimed to show the presence of OSA in stroke can contribute to the increasing chance of mortality and morbidity. We presented a case of first-time stroke in a 64-year-old female with a history of pre-stroke OSA. She underwent intravenous thrombolysis as main therapy within the time limit under 4.5 hours since the stroke onset. She had prolonged hospital stay due to complications from OSA, even though she only had a small ischemic core (9 mL) in follow-up radiological imaging and was discharged with a greater National Institutes of Health Stroke Scale (NIHSS) score than admission (5 to 10). OSA can be one of warning signs for poor prognosis in stroke patients. Understanding the presence of OSA not only can be beneficial toward choosing the next steps of therapy, but also important for the rehabilitation and recovery period of stroke patients. © 2024