A method for moving an instrument aim of a laparoscopy robot into a predeterminable position relative to a trocar placed in a patient is proposed. A spatial marker that can be localized from outside of the patient is applied to the trocar. The spatial position of the trocar is detected based on the spatial marker. The intended position of the instrument arm is established from the spatial position and the relative position. The actual position of the instrument arm is detected. The instrument arm is moved into the intended position based on the actual position, the intended position and an error minimization method.