A device and a method for the dilution and preparation of antiballistic drugs, the device comprises a drug preparation unit connected to a controlling device; the drug preparation unit comprises a first central tank, in which there is a solvent, typically a physiological and/or glucosate solution, a first positive-displacement pump, an emptying unit connected to a positioning and locking arrangement provided with a housing suitable for receiving various dimensions and formats of dimensions and formats of bottles of drug; the first positive-displacement pump transfers in a dosed manner the solvent from the central tank to the bottle, and in succession from the bottle to a further tank of semifinished drug; the diluted drug solution in the further tank is then transferred to a container of prepared drug in a determined quantity for infusion into a patient.