This paper studies the problem of designing an H-infinity. fuzzy feedback control for a class of nonlinear systems described by a continuous-time fuzzy system model under sampled output measurements. The premise variables of the fuzzy system model are allowed to be unavailable. We develop a technique for designing an H-infinity. fuzzy feedback control that guarantees the L-2 gain from an exogenous input to a controlled output is less than or equal to a prescribed value. A design algorithm for constructing the H-infinity fuzzy feedback controller is given. (C) 2003 Elsevier Ltd. All rights reserved.