Abstract: A dual lumen gravity oriented breast prosthesis or implant for surgical implantation includes inner and outer lumens which are defined by inner and outer closed envelopes of a medical grade elastomer. The outer closed envelope or lumen defines a generally oval or tear-shape with upper and lower portions. The outer envelope also contains a quantity of fluid material as for example a silicone gel having a first density. The prosthesis also includes a second or inner lumen defined by a second closed envelope of medical grade elastomer which is disposed in and fixed in the lower portion of the outer closed envelope. The inner lumen may be of various shapes such as generally spherical or preferably crescent shape. The second lumen is filled with a saline solution which has a density which is greater than the density in the outer lumen.