This paper describes an iterative linear matrix inequality (LMI) approach to the design of a structurally constrained output feedback controller. The structured synthesis is formulated as a novel rank-constrained LMI optimization problem, where the controller parameters are explicitly described so as to impose structural constraints on the parameter matrices. An iterative penalty-function method based on heuristics is used to solve the rank-constrained LMI problem. A numerical experiment illustrates the practicality of the proposed method. (C) 2006 Elsevier Ltd. All rights reserved.