Abstract: An adjustable mammary prosthesis for augmentation mammoplasty is comprised of an outer teardrop-shaped, gel filled distensible container or shell. Disposed within the outer shell is an extensible column-shaped container with a valve. The projection (H.sub.1) of the prosthesis can be altered without altering the base diameter (B) of the prosthesis by adding an appropriate volume of fluid to the column-shaped container via the valve to extend it axially and to increase its height and the projection (H.sub.2) of the outer container. In another embodiment, a pillow-shaped distensible inner container is positioned between the top of the extensible column-shaped inner container and the underside of the top of the outer container.