This paper is concerned with the H-infinity control problem via state feedback for fast sampling discrete-time singularly perturbed systems. A new H-infinity controller design method is given in terms of solutions to linear matrix inequalities (LMIs), which eliminates the regularity restrictions attached to the Riccati-based solution. A method for evaluating the upper bound of singular perturbation parameter epsilon with meeting a prescribed H-infinity performance bound requirement is also given. Furthermore, the results are extended to robust controller design for fast sampling discrete-time singularly perturbed systems with polytopic uncertainties. Numerical examples are given to illustrate the validity of the proposed methods. (c) 2008 Elsevier Ltd. All rights reserved.