In casting metal objects in casting cavities (2) in moulds (1), connectable to a pressurized mould-filling furnace (5) through a delivery tube (8) and a connector (9), an external riser (13) is connected to and extends upwardly from the junction of the tube (8) and the connector (9). The riser (13) is used as a temporary reservoir in which the level of molten metal is regulated by controlling the gas pressure in space 7 in the furnace (5) such that the filling head, defined as the difference in level between the metal in the casting cavities (2) and that in the external riser (13), is kept constant or made to vary in a desired manner, e.g. so as to cause the level in the cavities to ascend at a substantially constant rate. The invention makes it inter alia possible to produce high-quality aluminum castings in sand moulds, e.g. using automatic foundry equipment of the DISAMATIC® type.