In this communication, a multi-objective optimization method is implemented using evolutionary algorithm techniques in order to determine optimum configuration of solar chimney power plant. The two objective functions which are simultaneously considered in the analysis are power output and capital cost of the plant. Power output of the system is maximized while capital cost of the component is minimized. Design parameters of the considered plant include collector diameter (D-coll), chimney height (H-ch) and chimney diameter The results of optimal designs are obtained as a set of multiple optimum solutions, called 'the Pareto frontier'. For some sample points of Pareto, optimal geometric is presented. In addition, effect of changing design variables on both objective functions is performed. This multi-objective optimization approach is very helpful and effective for selecting optimal geometric parameters of solar chimney power plants. The results show that, power output of the plant increases linearly when solar irradiation increases and increase in ambient temperature causes slight decrease in power output of the plant. (C) 2014 Elsevier Ltd. All rights reserved.