This study explored the relationship between strategic management practices and environmental sustainability of electricity distribution firms in South-South, Nigeria. The motivation for this study is the need for the development of organizations' practices oriented towards sustainability that can have a positive impact on the sustainable management and ecological responsibility, which are increasingly present in today's environmental issues. Strategic planning, strategy formulation, strategy implementation, and strategic control were the measures of strategic management practices. The theories of dynamic capabilities theory, stakeholder theory and resource-based view theory have been used as a basis of the study. This research used the cross-sectional research design and it was anchored on the positivism philosophy. The subjects of the study were eight hundred ninety-eight (898) respondents of PHCN and BEDC. It resulted 278 respondents based on Taro Yamane formula, stratified and simple random sampling technique. The data were collected through primary data which was in the form of structured questionnaires. Descriptive statistics and Spearman rank correlation coefficient were used to analyse data at 5% level of significance. The results obtained, showed that the four dimensions of strategic planning namely strategic planning, strategic formulation, strategic implementation and strategic control were positive and statistically significant with the environmental sustainability. The study concluded that strategic management activities led to high level of improvement in environmental sustainability management. The study recommended on the need for more sustainability planning, effective implementation of strategies, more sustainability-oriented policies and environmental monitoring. The study added to the body of knowledge offering empirical data on the linkage between strategic management and environmental sustainability of the public utility organisations in Nigeria.