Abstract: A prosthetic heart valve assembly of the type having a ring member and pivotable leaflet structure is provided. Each individual leaflet pivots on a pair of peripheral flat ear members that oscillate in mating respective spherical bearing recesses. These recesses are formed in separate bearing blocks that radially seatingly engage mid-wall holes in a rigid, cross-sectionally C-configured ring member. Retaining means holds the bearing blocks in association with the ring member. Edge portions of the ear members and adjacent leaflet edges wipe the recesses and adjacent bearing block surfaces, thereby to avoid blood stagnation and clotting.