Many factors may affect sleep in the neurosurgery intensive care unit (NSICU), including therapeutic and diagnostic procedures, medications, the underlying disease process, and noise generated in NSICU. This study was aimed to determine the factors and nursing interventions, which affect the patients' sleep in NSICU, and to ascertain future descriptive research studies in nursing. The sample consisted of 84 voluntary patients hospitalized at a university hospital. They were consecutively asked to fill out a questionnaire in face-to-face interviews, and on the same day they were transferred out of the NSICU to a neurosurgical ward. Sixty-six patients (78.6%) experienced sleep disturbances. In those patients, being kept immobile (63.6%) and being in a noisy environment (57.6%) were the factors, which most frequently disturbed sleep. Likewise, the nursing interventions were found to have profound influences on patients' sleep; namely, being asked to move an arm/leg or to keep them in the same position for neurological diagnostic reasons (43.9%), and being asked questions to determine the level of consciousness (40.9%) were identified as the common sleep disturbance factors. In conclusion, immobility, environmental noise factors, and the disturbances from implementing the nursing interventions should not be ignored. Sleep disturbance in NSICU should be addressed on the multidisciplinary care plan and in health team conference, and care should be planned to assure good quality of patients' sleep. Nurses, physicians, nursing and medical students should establish and evaluate the combined interventions required for neurological assessment to decrease the negative effects of various factors on patients' sleep.