IntroductionOrganisations, though different in sizes and structures, are all set for achieving goals and objectives. As organisations differ in what they do so also are their goals and objectives. To attain the set goals, organisations need people to drive the process of which these individuals come on board with their different dispositions and attitudes. Nelson and Quick (2019) contend that an organisation has four internal components: task, technology, structure and people. Out of these components, people are central to all. Researchers (Nelson and Quick, 2019) further opined that people or human resources in the organisation have behaviour as individuals and as a group, hence studying people's behaviour at work. Mullins and Christy (2016) argued that people are the primary resource of any organisation. Therefore, individuals and groups actions that could be positive or negative must be understood, predict and control to improve organisational performance and effectiveness. In relative terms, Scandura (2018) posited that firm behaviour is of immense importance because it can yield some outcomes like performance, work-related attitude, employee well-being, motivation and employee withdrawal. Furthermore, the dramatic change witness in organisations as a result of work/ cultural diversity, ageing employee, usage of the temporary workforce, technological advancement, global competition, increase work flexibility, employment options and the likes has brought about the need for business owners and managers to understand the behavioural trend and deploy organisational behavioural concept for optimal performance of the firm (Robbins &Timothy, 2016). However, Nelson and Quick (2019) opined that the study of human behaviour contributed to different courses like Psychology, Anthropology, Engineering, Sociology, Management and Medicine, which makes it multidisciplinary.Based on the importance of organisational behaviour (OB), the study investigates the impact of organisational behaviour on organisational performance, focusing on Nigeria's health care institution. Likewise, in future which is already here, the study aims to draw the focus of researchers towards the importance of the subject in the discussion as it determines the success and failure of every organisation.However, health institution as defined by Law insider dictionary is an organisation that primarily has a purpose of care and treatment of patients or promotion of public health of which could be the hospital, nursing home, convalescent home, maternity home, health centre, dispensary or other body where health or other medical services are rendered. In the relative vein, Encyclopedia of Bioethics explained health institution to be the hospital, a nursing home, a rehabilitation facility, or another such single-site entity where people work at different capacities and have leaders who direct their affairs like hiring, firing and setting of policy. Considering the earlier definitions, health care services are provided in health institutions no matter what they...