An assembly for collapsing a self-expanding prosthetic heart valve includes a compression member, a support member, a constricting member, and a spacer which may be used for smaller sized heart valves. The compression member has a tapered wall between its first open end and its second open end, the tapered wall defining an open space adapted to receive the heart valve. The support member has a base and a recess adapted to receive an end of the heart valve. The support member and the compression member are movable toward one another to compress the heart valve and push it through a relatively small aperture in the second open end of the compression member. The second end of the constricting member is sized to receive the compressed heart valve from the second open end of the compression member for loading into a delivery device.