Utilization potential of fly ash, as the main residue in the lignite coal combustion in Serbian power plants, was investigated in present study. High production of fly ash represents extreme hazard for environment. Question of storage of this waste material is disclosed. Recycling and reapplication of fly ash in construction materials industry is only economic solution for ongoing problem. Fly ash can be used as a component in cement, mortar, concrete, bricks, and tiles. In this study, characterization of three different Serbian fly ash capacities was used as base for further fly ash utilization possibilities investigation. Investigation of fly ash mineralogical components as well as chemical composition analysis was emphasized. Macroperformance was correlated to the microstructure of fly ash studied by means of XRD and SEM analysis. Furthermore, thermal stability of crystalline phases, content of trace elements, physico-chemical characteristics, and leaching toxicity were tested. Highlight was placed on the determination of the influence of the fly ash grain-size and its microstructure on the performances of the fly-ash-based products. Comparison of Serbian fly ash properties with characteristics of foreign fly ashes led to the presumption that Serbian fly ash has equal if not better characteristics and that it can be reapplied in production of high-value products manufacturing worldwide.