A dropper machine for pouring a measured amount of a substance in a plurality of receptacles (R), comprising:- a support structure (4),- a reservoir (6) containing the substance to be dropped, supported by said structure,- a plurality of cylinder (10) and piston (12) metering devices (8) with an inlet (18) positioned below the level of the substance to be dropped into the reservoir (6) and an outlet (10a) communicating with a respective dropper nozzle (16),- at least one drive unit (100A, 100B) arranged to simultaneously drive the piston of said metering devices (8) according to a forward and backward motion between a start position and an end position where the displacement of the pistons (12) from the end position to the start position causes the suction of the substance to be dropped from the reservoir (6) to the cylinder (10) of the metering devices and the displacement of the pistons (12) from the start position to the end position is adapted to cause the delivery of the substance to be dropped through the respective nozzles (16), characterized in that to each of said metering devices (8) is associated a respective actuating device (24) cooperating with the piston (12) of said metering device, said actuator device being operable individually to inhibit the delivery of the substance to be dropped through said nozzle (16) when the drive unit (100A, 100B) is actuated to cause displacement of the pistons of the metering devices associated therewith between the start position and the end position.
