A portable perfusion/oxygenation module includes respiratory gas driven dual positive displacement pumps coupled to a stacked membrane oxygenator unit for perfusion fluid oxygenation, a valving manifold to control perfusate flow-direction coupled to an organ chamber designed to enable easy installation of organ and maintenance of intra and extra organ fluid pressure. All of the components and oxygen cylinders are fitted into an insulated chest capable of sustaining perfusion and oxygenation for 24 hours. The perfusion/oxygenation apparatus requires no electrical power, is compact with the total weight including the perfusion fluids and organ weighing less than 50 pounds. With low cumulative weight and the extremely low flow rate of gas required to pump the perfusate, the oxygen supply is capable of sustaining pumping operation for 24 hours without gas cylinder change. The dual pumps have axially aligned, commonly connected pistons using adjustable linkages that provide a simple and robust means of adjusting perfusate volume and pumping rate. No movable membranes, diaphragms or electrical power are required to deliver oxygenated perfusate.