Aims and background: Mining and energy complexes in Serbia are recognized as a major source of a large number of pollutants. Serbia’s environmental performance reports clearly indicate that large mining and energy complexes are the dominant source of air pollution. It is difficult to determine which of them remarkably threaten the quality of the environment, as all the basic elements of the environment (air, water, and soil) are threatened, not just one. Mining and energy complexes significantly reduce the quality of the immediate environment, as the distance areas throughout water and air pollution propagation. Additional motivation for this study lies in the fact that large mining and energy complexes are particularly interesting because they are located in the immediate vicinity or large rivers (mostly the Danube), which are protected in many national and international legislation acts (particularly the Danube). The basis for the preservation of environmental quality is an effective environmental management system (EMS) in mining and energy complexes. The aim of this study is to promote and elaborate the possibility for improving the mining and energy complex environmental protection/management system by applying the basic principles of sustainable development. Methodology: Project management methodology is selected as a tool. Project management is based on the application of a network planning technique (Critical Path Method), because of its suitability for representing the logical structure of environmental protection system. The survey was conducted in the area of the city of Kostolac. The examined area included mining and energy complexes in Kostolac, which incorporate three surface mines (Ćirikovac, Klenovik, and Drmno) and two thermal power stations (TE “Kostolac A” (100 MW) and TE “Kostolac B” (2 × 348.5 MW)). The PSR model (Pressures, State, Response) was used for the organization of the interactions within “society⁻environment” system as the basis for indicator selection. Results: Procedures to identify and determine the significance of the environmental aspects should be established by executive staff in mining and energy plants and complexes. Identification of environmental aspects is the first part of the planning system of environmental management and the activities related to them. The accomplishment of critical path activities represents the basis for improving the environmental protection system in mining and energy complexes. Discussion: Application of sustainable development principles depends on the country’s energy potential and the application of the adopted environmental policy regarding mining and energy complexes. Strict enforcement of existing laws and regulations presents an opportunity to rectify many shortcomings while providing economic benefits, restoring the usable value of ravaged land, and preserving air and water quality.