Background: Cardiovascular diseases are the leading cause of death globally. Controlling and managing stress and stressors experienced by sick patients should be undertaken by all care providers. Professional nurse play an important role in the pre and post-operative care of the patient undergoing open heart surgery for obtaining a positive outcome. Aim: This study aimed to assess stressors on patient’s pre /post of open heart surgery in El Sheikh Zayed Specialized Hospital. Design: A descriptive exploratory design was utilized in this study. Subject: A convenience sample of (135) patients. Setting: This study was conducted in the open heart Intensive Care Units at El shiekh Zayed specialized Hospital. Data collection tools: Tool (I)A structured Interview Questionnaire. (Part1): Socio-demographic data.(Part2): Patient Medical Data. (Part3): patient’s Life style. Tool (II): The Intensive Care Unit Environment Stressors Scale (ICUESS) Results:65.9% from studied patients had moderate level of environmental stressor pre-operative, 79.3% from studied patients had moderate level of environmental stressor post-operative, while 86.7% from studied patients had moderate level of total environmental stressor. Highly statistically significant relation between socio-demographic characteristics, length of hospital stay, frequency of ICU admissionand total level of ICU environmental stressors among the studied patients. Highly statistically positive correlation found between total score of pre-operative environmental stressors and total score of post-operative environmental stressors. Conclusion: Highly statistically positive correlation between total score of pre-operative environmental stressors and total score of post-operative environmental stressors. Recommendations: In the level of education, multi-dimensions for open heart patient's assessment to stress level before cardiac surgery should be carried out to consider interventions aimed at reducing post-operative complications and enhance recovery in these patients.