A device for supporting a patient for stereotactic on-target radiation therapy in the head region of the patient includes a supporting table with a tabletop movable at least in the horizontal plane, and a holding means for arranging a stereotaxis unit fixed on the head of the patient. The holding means is arranged on the tabletop and is associated with the head region of the patient projecting beyond the tabletop. This device provides aiming accuracy also with not highly rigid connections between a stereotaxis unit and the skull of a patient. This device provides a connection means permitting free relative movability at least in the longitudinal direction of the table or the patient, and at least temporarily between the tabletop and the stereotaxis unit.