The number of applications with the popular generalised predictive control (GPC) algorithm has risen considerably since the early years following its introduction. It is reaching a wider audience including clinicians, perhaps due to recent progress in the understanding of the design of model-based predictive control in general, followed by an awareness of the criteria governing the choice of the GPC ’tuning parameters’ which can be tailored to a specific application. The development and evaluation of SISO GPC for on-line administration of muscle relaxant drugs in the operating theatre during surgery is considered first. Excellent regulation has been achieved with good robustness properties against surgical disturbances such as diathermy. The work has been extended to the multivariable case involving simultaneous control of muscle relaxation and unconsciousness using blood pressure monitoring. Results of preliminary trials are very encouraging.