Abstract: A one-piece prosthesis for use by a woman who has undergone a mastectomy, the prosthesis comprising the form of a complete breast, without voids therein, and with a supplement extending toward the axilla, and a supplement extending toward the clavicle, each supplement designed to fill a void left by surgery, and further having a band below the breast to underlie the lower band of brassiere, said supplements and band being tapered to a fine edge of avoid the appearance of demarcation lines. The prosthesis is molded of silicone which may contain dye to match skin coloration, and approximates the size, shape, density, resilience and pliability of the natural breast in various chest and cup sizes.