Among power generation systems, CCPPs (combined cycle power plants) are attractive due to their higher efficiency and lower environmental impacts. Optimization process is a promising manner in order to find the best performance criteria of complex energy conversion systems. In present paper, exergoeconomic analysis and optimization of a triple-pressure combined cycle plant with one reheat stage is under investigation. The objective function which is utilized in the optimization study is the total cost rate of the plant. The results show that optimization process leads to an increase of about 3% in both energetic and exergetic efficiencies and also, a reduction of about 9% in the cost criteria. In addition, the specific cost of product of the plant is reduced from 21.48 ((sic)/h) for the base case to 20.90 ((sic)/h) for the optimum case; thus, the optimization process causes about 3% decrement in the specific cost of product and consequently cost of produced electricity. (C) 2015 Elsevier Ltd. All rights reserved.