This study focuses on developing reduced-order models for unsteady aerodynamic flows past a cascade of two-dimensional airfoils. A reduction method known as System Equivalent Reduction Expansion Process (SEREP) is used. The computational efficiency of the SEREP reduced-order model is compared with a reduced-order model formed using the Proper Orthogonal Decomposition (POD) technique. The present study shows that the SEREP is computationally more efficient than POD. © 2003 Elsevier Ltd. All rights reserved.