Abstract: An ankle block for joining a leg prosthesis to a foot prosthesis includes a generally cylindrical member formed of rigid foam material, and a metal or wood insert molded in place in the lower end of the cylindrical member. The insert includes flanges which anchor it firmly in the foam, and a hole extending axially therethrough for receiving and anchoring a bolt from the prosthetic foot. An upper cylindrical passage extends from the upper end of the block to the insert, and a lower cylindrical passage of smaller diameter extends likewise from the lower end. The insert is adapted to receive and anchor either a bolt from a Sach foot, or a tee-bolt from a single-axis foot prosthesis.