Background: Enhancing competency in the care of patients with intercranial hypertension is recommended to maintain nursing knowledge base and practice levels. Ongoing nursing education regarding management of those patients is required for nurses to provide optimal care and improve patients' outcomes. Aim of the study: Determine the effect of guidelines regarding care of intracranial hypertension patients on critical care nurses' knowledge and practices. Design: A quasi-experimental design was utilized to conduct the current study. Setting: This study was conducted at the critical care units (Intensive Care Unit and Neuro-Critical Care Unit) in Suez Canal University Hospitals. Sample: A purposive sample of 80 nurse was enrolled in this study from 1st of December 2021 to the end of May 2022. Tool of data collection: two tools were used, tool )I(: a Self-administered knowledge questionnaire to assess demographic characteristic and level of nurses' knowledge and tool )II( an observational checklist to assess nurses' practices for caring of patients with Intracranial hypertension. Results: There was a statistically significance differences between pre/ post & follow up guidelines implementation regarding knowledge and practices of the studied nurses caring for patients with intracranial hypertension. Conclusions: Educational nursing guidelines were effective in the improvement of knowledge and practice levels of the nurses' caring for patients with intracranial hypertension. Recommendations: Implementing orientation and periodic in-service training program for nurses regarding care of patients with increased intracranial hypertension.