A prosthetic heart valve provided herein can include a kidney capsule tissue leaflet. In some cases, a prosthetic heart valve can include a plurality of leaflets secured together and retained within the expandable tubular member. The kidney capsule tissue can be obtained from a farm animal, such as a cow, pig, horse, goat, or sheep. In some cases, the kidney capsule tissue can be tensioned (e.g., bi-axially tensioned) and/or chemically cross-linked.