This paper presents an adaptive control scheme based on a fuzzy logic algorithm and its application to end-effector positioning of flexible-link manipulators. Here, a fuzzy based adaptive controller is considered due to its simplicity and the fact that it does not require expressing the controller in terms of the system parameters, as is necessary in the case of self-tuning regulators. This controller is based on a functional fuzzy model where the consequents are crisp functions of the system states and/or inputs; these functions represent controllers designed for different operating regimes. The premise is constituted by the fuzzy subsets corresponding to the process parameters estimated in real time. The effectiveness of this new scheme is verified on a clamped-free beam and a single-link flexible arm instrumented with piezoceramic sensors and actuators. It will be shown that robust performance may be achieved in face of large parameter variations.