Twenty years ago in the Belchatow power plant in Poland the first flue gas desulfurization (FGD) were launched, in which as a by product a synthetic gypsum is obtained. In accordance with international commitments the desulfurization has been implemented gradually in many other domestic power plants. As a result of introduced wet limestone scrubbing method large quantities of synthetic gypsum appeared on the construction materials market. This article is an attempt to assess changes in the market of gypsum in Poland as an effect of the flue gas desulfurization. The state of the gypsum mining in past two decades has been presented. The process of the implementation of FGD along with potential and real gypsum production in polish power plants has been described. The utilization of synthetic gypsum from power plants were discussed. The production of natural and synthetic gypsum in the last two decades has been compared. Using official plans of the development of polish energy production the forecast of the synthetic gypsum in the next years has been made. In the case study basing on one lignite deposit, which development is planned, the forecast of the future synthetic gypsum production from FGD in the planned lignite power plant has been made. In the summary were emphasized that the changes in the mineral resources management, especially sulfur compounds, are the result of the technological progress, which the main driving force is the need of environment protection.