The invention relates to a system and a method for cooling moulds of a machine used to form hollow glass items, of the type that comprises arms for carrying mould halves movable between a closed mould position and an open mould position, each mould half having axial passages for the cooling thereof. The system allows the adaptation thereof to different sizes of mould and the cooling of the mould halves in any position between the closed mould position and the open mould position. To this end, it has a height-adjustable upper plate on which a chamber for the distribution of cooling fluid to the axial passages of the moulds is moved, cooling ducts being connected to said upper plate so as to provide cooling fluid from a plenum box.
