Introduction: The World Health Organization (WHO) Surgical Safety Checklist (SSC) launched in 2009 was developed to address preventable causes of morbidity and mortality in the perioperative period by promoting communication among all team members and ensuring that all necessary safety checks are done as and when due and that they are done appropriately. Studies have shown that implementation of the WHO checklist reduces the risk of SSI and preventable deaths by about 50%. Thus, it is encouraged that all hospitals, domesticate the tool to improve patient safety. The study aims to assess the level of usage of the WHO SSC, the gaps in its implementation and to evaluate the awareness, perception and acceptability of this tool among theatre staff personnel at a tertiary hospital in Nigeria. Materials and methods: We prospectively conducted an audit of the use of the WHO SSC at the main and emergency theatres, University College Hospital, Ibadan by observing the level of implementation of the different events in the WHO SSC using a pre-developed questionnaire. We subsequently conducted a survey on the awareness, perception and acceptability of the WHO SSC among the operating team personnel using a 15-item self-administered questionnaire. The data were analysed with SPSS. Results: A total of 117 surgeries were observed during the audit and 81 surgical team personnel took part in the survey. The WHO SSC was used in about half (52.1%) of the surgeries and it was sparingly used during minor surgeries (5.4%). The Sign Out Phase was the least completed phases of the checklist. The personnel administering the check list (usually the circulating nurse) did not ask the scrub nurse the required questions in more than half of the time (53.1–58.7%) in the Time Out Phase and this was significantly higher when compared with unasked questions to other professionals of the team (11.3–15.6%). In the Sign Out Phase, of the five questions, four questions were barely asked in about half of the time (44.6–76.8%). Eighty-one per cent personnel were surveyed, half (50%) were surgeons and about a quarter were anaesthetists (23%) and Nurses (27%). More than half of respondents (58%) have more than 5-year work experience in the hospital. Majority (65.4%) of members of the surgical team had not had any formal training on the WHO SSC. About a third of respondents (28%) who had made an error in surgery agreed that it could have been prevented by proper implementation of the WHO SSC. The respondents also agree that the sign out phase was completed in less than a third (27.2%) of the time. There was no difference in its awareness, perception and acceptability based on profession of the respondents. Conclusion: The WHO SSC should be made available at all theatres in the hospital and should be administered during all surgeries. There should be more formal training of members of the surgical team to improve implementation. Assessing for the barriers to the implementation of the WHO Safety Surgical Checklist is the logical next step to improve the use in our theatre.