A method and transfer device for transferring fluids between closed vials. The transfer device includes a cylinder having a pair of opposing open tubes or tubular portions into which a pair of vials can be inserted to transfer fluid therebetween. The tubes are separated by a wall through which extends a fluid transfer needle and a vent needle which first is inserted into a first vial to vent the first vial into a vent chamber or reservoir formed in the transfer device before the transfer needle is inserted into the first vial. The first vial, stopper first, is inserted into first tube until seated onto an exposed end of the transfer needle. A second vial, stopper first, then is inserted into the second tube until seated onto the opposite exposed end of the transfer needle. A pressure differential between the closed vials preferably can be utilized to transfer a desired fluid portion between the vials.