The present invention relates to the implantation of one or more prosthetic valve(s) in the pulmonary vein(s) of a subject as a means of decreasing or preventing an increase in pulmonary venous pressure. The present invention accordingly provides for novel treatment strategies for the treatment of medical disorders associated with elevated pulmonary venous pressure, including congestive heart failure, as well as for prosthetic pulmonary vein valves and their delivery systems. Expandable as well as fixed-dimension non-expandable pulmonary vein prosthetic valves for implantation by a variety of surgical and percutaneous procedures are also described.