A breast prosthesis comprises a resiliently-compliant silicone shell (1；11) which has an outer wall (2；12) configured to simulate the shape of a female breast. The wall (2；12) is fretted with an ornamental pattern of perforations (6；16) that vent the internal cavity (4；14) of the shell (1；11), and ribs (5；15) within the cavity (4；14) extend across it in resiliently supporting and retaining the breast-shape of the shell (1；11). The ribs (5；15) are interconnected with one another and are moulded integrally with the outer wall (2；12). The shell (1:11) has a flat peripheral rim (3:13) to the cavity (4:14).
