In a method for controlling the administration of insulin to a patient, a target glucose level is set and a controller computes a recommended infusion rate based on the target glucose level and a measured glucose level of a patient for administering insulin to the patient. The controller uses a controller gain for computing the recommended infusion rate. Herein, an insulin sensitivity of the patient is determined using a mathematical model taking into account the measured glucose level and an actual infusion rate of insulin administered to the patient and, based on the insulin sensitivity, the controller gain of the controller is determined. In this way a method for controlling the administration of insulin to a patient is provided which in a reliable, computationally efficient manner allows for maintaining a patient's blood glucose level at or around a desired target glucose level.