Flexibility is often an unavoidable consequence of the desire for high speed and performance manipulators. This paper proposes a method that improves the performance of flexible manipulators through the employment of robust state estimation techniques. These techniques are based on discrete time Kalman filtering and sliding mode principles. A simple model for a single degree of freedom flexible manipulator is derived and a control scheme is chosen and implemented. The latter includes a robust non-linear estimator. Simulation and preliminary experimental results are presented that demonstrate the validity of the proposed control scheme.