This paper presents a robust single-input multi-output design approach for governors for speed control of hydro-turbines. A nonlinear turbine model is developed to include effects of water hammer, travelling waves and inelastic water penstocks. Norm bounded uncertainties and disturbances are briefly discussed to investigate measures of robustness. The polynomial robust H-infinity optimisation method is used in design. The robust governor ensures that the overall system remains asymptotically stable for all norm bounded uncertainties and permanent system oscillations. Results are compared with conventional PI and PID designs and presented in the time and frequency domains. It is demonstrated that the proposed robust governor improves the performance significantly even in the presence of uncertainties. (C) 2003 Elsevier Ltd. All rights reserved.