A method for determining the spatial position of objects, in particular medical objects, comprising the steps of: - acquiring, by means of a medical tracking system comprising a sensor array, first position data which comprise first position information describing the spatial position of an object within a first co-ordinate system positionally assigned to said sensor array which is configured to determine the spatial position of at least one tracking marker attached to the object; - acquiring first transformation data which comprise first transformation information describing a transformation of the object's position from the first co-ordinate system into a second co-ordinate system positionally assigned to an inertial sensor array which is attached to the medical tracking system's sensor array and configured to sense any motion of the medical tracking system's sensor array within an inertial co-ordinate system positionally assigned to a treatment room which accommodates the object; - acquiring, on the basis of the first position data and the first transformation data, second position data which comprise second position information describing the spatial position of the object within the second co-ordinate system; - acquiring second transformation data which comprise second transformation information describing a transformation of the object's position from the second co-ordinate system into the inertial co-ordinate system; - determining, on the basis of the second position data and the second transformation data, inertial position data which comprise inertial position information describing the spatial position of the object within the inertial co-ordinate system. - acquiring, by means of a medical tracking system comprising a sensor array, first position data which comprise first position information describing the spatial position of an object within a first co-ordinate system positionally assigned to said sensor array which is configured to determine the spatial position of at least one tracking marker attached to the object; - acquiring first transformation data which comprise first transformation information describing a transformation of the object's position from the first co-ordinate system into a second co-ordinate system positionally assigned to an inertial sensor array which is attached to the medical tracking system's sensor array and configured to sense any motion of the medical tracking system's sensor array within an inertial co-ordinate system positionally assigned to a treatment room which accommodates the object; - acquiring, on the basis of the first position data and the first transformation data, second position data which comprise second position information describing the spatial position of the object within the second co-ordinate system; - acquiring second transformation data which comprise second transformation information describing a transformation of the object's position from the second co-ordinate system into the inertial co-ordinate system; - determining, on the basis of the second position data and the second transformation data, inertial position data which comprise inertial position information describing the spatial position of the object within the inertial co-ordinate system.