A device for reconstituting liquid for medical use by bringing together a first liquid medium contained in a first vessel in the form of a cartridge (3) and a second medium, such as a drug in solid form, contained in a second vessel in the form of a vial (7), the device (19) comprising means (41) for supporting the first and second vessels, and a movable operating member (50) for applying a force to cause the first liquid medium to be delivered at a controlled rate from the first vessel into the second vessel. The first and second vessels may be provided in a pack (70) having liquid transfer means in the form of a needle (10). <;IMAGE>;