Background: Deep vein thrombosis (DVT) is a major complication and preventable cause of morbidity and mortality among patients in the intensive care unit (ICU). The incidence of deep vein thrombosis in neurological ICU presumed to be higher reporting an incidence of 18 to 50%. A nursing protocol that improves nurses' use of preventive measures for deep vein thrombosis is paramount. Aim: This study aimed to investigate the effect of nursing care protocol on deep vein thrombosis occurrence among critically neurological patients.Subjects and Method: Design: A quasi-experimental research design was used.Setting: study conducted at neurosurgery intensive care unit and neurological department in Mansoura University HospitalSubjects:a purposive sample of 60 patients (30 protocol patients group and 30 control group) participated in the study.. Routine care was applied to the control group while the protocol group received deep vein thrombosis care according to the protocol. Tools: data were collected using two tools; DVT Assessment Status Tool and DVT Incidence Monitoring Tool. Results: 26% of studied patients in the control group developed DVT compared with 3%  in the protocol group. A significant difference existed between the two groups after implementing the nursing protocol concerning exercise, elastic stock, and pneumatic compression (P<0.05). Conclusion and recommendations: The proposed protocol for nursing care is substantially successful in reducing DVT among critically neurological patients. It is recommended to train healthcare staff to use this protocol.