Obstructive sleep apnea syndrome (OSAS) is a serious and often underreported condition, despite its highly prevalent distribution. It's found in over 60% of patients with stroke and identified as an independent stroke risk factor. Nurses play an integral role in assessing and managing patients with a high risk of developing OSAS. Aim: To evaluate nurses' knowledge level related OSAS associated with stroke. Method: Design: Descriptive Cross sectional research design was utilized. Sample/Setting: A convenient sample of nurses working in Al-Sadder teaching hospitals (STH), Iraq and Neurology Ward Mansoura University Hospitals (MUH), Egypt who met inclusion criteria was selected. Tools: The one tool were collected by using structure interview questioner two parts a validating questionnaire; a demographic data form, and nurses’ Nurses’ Knowledge Related to Obstructive Sleep Apnea Syndrome. Results: The majority the studied nurses at MUH had satisfactory level of knowledge related Obstructive Sleep Apnea Syndrome, whereas more than half of the studied nurses at STH (59.2%) had unsatisfactory level. Conclusions: A difference in the level of nursing knowledge related to Obstructive Sleep Apnea Syndrome patients between Iraq and Egypt. Recommendations: Providing continuous in-service education for nurse’s knowledge related to nursing care with obstructive sleep apnea syndrome. Hospital libraries should also play an active role in providing materials that can help nurses to read related to obstructive sleep apnea syndrome.