Introduction: Surgical safety remains a critical concern globally due to the significant risk of adverse events during operative procedures, and perioperative nurses play an important role in ensuring safe surgical care through adherence to established safety standards.

Objective: The study assessed knowledge and the level of implementation of perioperative safety standards in the operating theatre of UNIOSUN Teaching Hospital, Osogbo, Osun State.

Method: An observational study using a quantitative research method was conducted. Data were collected from 14 perioperative nurses using a self-designed questionnaire developed from the World Health Organization surgical safety checklist and Association of Perioperative Registered Nurses guidelines. Descriptive statistics were used to present frequencies and percentages.

Results: All 14 participants (100%) were classified as having good knowledge of perioperative safety standards. Twelve (85.7%) reported a high level of implementation, while two (14.3%) reported a low level. Use of the WHO surgical safety checklist and surgical smoke evacuation were identified as areas requiring improvement.

Conclusion: Participants demonstrated high self-reported knowledge and implementation of perioperative safety standards. However, sustained compliance requires continuing education, supportive leadership, teamwork, adequate resources and audit-based monitoring. Self-reported findings should not be interpreted as direct verification of actual practice.