Disclosed prosthetic valves can comprise a sewing ring configured to secure the valve to an implantation site. Some disclosed valves comprise a resiliently collapsible frame having a neutral configuration and a collapsed deployment configuration. Some disclosed frames can self-expand to the neutral configuration when released from the collapsed deployment configuration. Collapsing a disclosed valve can provide convenient access to the sewing ring, such as for securing the valve to the implantation site, as well as for the insertion of the valve through relatively small surgical incisions.