Robust feedback control of a synchronous motor with model and parameter uncertainties and load disturbances is studied. The mathematical description of the motor in the (d, q) frame yields a bilinear model in state space form. The control strategy is based on a worst-case analysis and leads to the formulation of a min-max problem, whose solution provides an H-infinity bound for the noise-to-output transfer function. The design of the dynamic controller entails the solution of an appropriate Riccati equation.