In order to reduce the control design problem for input/output long-delay systems, a stable predictor is presented in this paper. The predictor is stable for stable/unstable or minimum/non-minimum phase systems. Based on the predicted undelayed output, any available control design procedure can be applied to fulfil the control requirements, the delay remaining unchanged. Disturbance rejection and robustness may be enhanced based on the estimation error. The approach is shown to work in all considered cases and comparison with other methods, when available in the literature, is reported. (C) 2009 Elsevier Ltd. All rights reserved.