Purpose: This study was conducted to investigate the effects of postoperative lateral positioning on the patients’ outcomes with subarachnoid hemorrhage. Materials and Methods: This study, which is a randomized controlled intervention study, was conducted with 42 (experimental group: 21, control group: 21) patients who underwent subarachnoid hemorrhage surgery in the neurosurgery intensive care unit of a university hospital and met the sampling criteria. In the study, "Patient Descriptive Information Form" and "Patient Results Form" were used as data collection tools. A total of 42 patients operated on for subarachnoid hemorrhage were included in the study. While the patients in the intervention group were placed in the left lateral, right lateral, and semi-fowler position (30 degrees) every 2 to 4 hours for the first 72 hours, those in the control group were routinely placed in the semi-fowler position (20 to 45 degrees). Results: The power of hydrogen value and partial oxygen pressure and arterial oxygen saturation at the 48th hour in the intervention group were statistically significantly higher than the control group at the 72nd hour. In the intervention group, a slight decrease was observed only in the heart rate at 72 hours, which was near normal. Conclusion: Lateral and semi-fowler positions with a 2 to 4 hour interval contributed to improved oxygenation and prevented secondary complications of subarachnoid hemorrhage.