A constrained generalized predictive linear control strategy is extended to constrained control of open-loop unstable nonlinear processes. In this strategy, process nonlinearities are accounted through adaptation of model parameters while taking care of input and output constraints acting on the open-loop unstable nonlinear process. The usefulness of this control strategy is evaluated by applying it to a chemical reactor and a biochemical reactor. The results show that this strategy is effective for control of open-loop unstable plants.