A system for handling objects in rotary machines, and, more particularly, a system for handling preforms in blowing machines. The system picks up a pre-heated preform from a transferring star of the preform and takes it to a mold of a stretch-blowing machine by using movements entailing reduced acceleration values, in particular of the tangential acceleration component, so as to prevent uncontrolled oscillatory movements of the softened preform. In the blowing machine, the preform is blown to obtain a bottle, and the bottle thus obtained is picked up from the stretch-blow molding position and transferred to an unloading position.