The global warming is a major thread in recent days. Industrial pollution is a prime contributor to global warming especially pollution due to coal fired power plants. In global electrical power scenario, maximum portion of required electrical energy is produced from coal fired thermal power plants. Steam turbine is major equipment in it, which converts heat energy in to mechanical energy. The energy conversion efficiency is most important one. Reduction in efficiency means wastage or loss of energy and leads to increase the cost of generation. Here, case study is conducted in the topmost coal fired thermal power plant in south India. The objective of the study is to recognize and evaluate the most influential drivers in the coal fired thermal power plant. If the most important drivers which highly influencing steam turbine efficiency are identified. In this paper, to recognize the most influential drivers for affecting steam turbine efficiency by using DEMATEL technique. The outcomes of the paper expose that steam pressure (D1) is the most influential driver in the coal fired thermal power plant and they need more focus to control it