A negative pressure injection device which includes a suction cup and an inner skirt that encircles an injection port and depends into the interior of the suction cup. An injection member is surrounded by and protrudes below the inner skirt. When air is drawn from the suction cup an epidermis of a patient is drawn into the suction cup until the epidermis comes into contact with the inner skirt and that portion of the injection member protruding below the inner skirt. The inner skirt provides consistent epidermis positioning. The depth of injection is consistently defined by the extent to which the injection member protrudes below the inner skirt.