<b>Macro Environment and Organisational Structure A Review</b> This piece of work theoretically or descriptively considered the impact of the external environment on the structure of organizations. The key variables being organizational structure the dependent variable and the external environment of the organization as the independent variable . Dimensions of organizational structure adopted were centralization, formalization, standardization, specialization and configuration while the measures of external environment applied were level of uncertainty or changeability, intolerance or xenophobia and complexity. The theoretical foundation was hinged on social identity theory and contingency theory. Meaning, types and factors affecting organizational structure were considered alongside environmental factors. It was observed that the external environment has great impact on the organization and is largely responsible for the dynamic nature of the business world. It was therefore recommended that an adequate environmental scanning be carried out to ascertain the stability or otherwise of the environment to be able to know which structural type to adopt at every point in time. Organizational Structure, Organizational Environment, Centralization, formalization, standardization, specialization, complexity, xenophobia, uncertainty 25-33 Issue-1 Volume-5 Hannah Chika, Anyanwu | Dr. Justin Mgbechi. O. Gabriel