A heart valve prosthesis (100) comprises a housing component (110) and a valve component (130). The housing component (110) comprises a housing body (111) having a housing passage (112) extending therethrough. The housing body (111) is configured to be located in, or adjacent to and communicating with, a native valve orifice (16) of a heart (10) and to engage structure of the heart (10) to fix the housing body (111) in relation to the valve orifice (161). The housing component (111) is collapsible for delivery via catheter (2). The valve component (130) comprises a valve body (131) having a valve passage (132) extending therethrough. The valve body (131) is configured to be fixed within the housing passage (112) with the valve passage (132) extending along the housing passage (112). One or more flexible valve elements (131) is/are secured to the valve body and extend across the valve passage (132) for blocking blood flow in a first direction through the valve passage (132) whilst allowing blood flow in the opposing direction. The valve component (130) is collapsible for delivery via catheter (2) separate to the housing component (110). An associated method of replacing a failed or failing heart valve utilising the heart valve prosthesis (100) is also disclosed.