Design of plate-fin heat exchangers is a very complex task generally based on trial and error process. Traditional designing methods are very time consuming and do not guarantee the archive of an optimal solution; therefore heuristic based computation methods are used, usually. So, in present paper a new design method proposed for optimization of plate fin heat exchangers using biogeography-based optimization (BBO) algorithm. The BBO algorithm has some advantages in detecting the global minimum compared with other heuristic algorithms. In present research the BBO scheme has been employed for optimal design of the plate fin heat exchanger by minimization of the total annual cost, heat transfer area and total pressure drops of the equipment considering main structural and geometrical parameters of the exchanger as design variables. Based on proposed approach, a full computer code was developed and three various case studies are investigated by it to illustrate the effectiveness and accuracy of the proposed method. Comparison of the results with those obtained by previous methods reveals that the BBO algorithm can be successfully employed for optimization of plate fin heat exchangers. Finally, parametric analysis carried out to evaluate the sensitivity of the proposed method to the cost and structural parameters. (C) 2015 Elsevier Ltd. All rights reserved.