Wales supported a network of hospitals, hospices, and leper houses stretching from the twelfth century to the seventeenth. This survey documents twenty-one confirmed and probable sites, from the earliest Hospitaller grant in Pembrokeshire before 1148 to the almshouse foundations recorded in the Bishop of Bangor's Return of 1665. It covers the great urban leprosaria at Cardiff and Tenby, the episcopal foundations at Llawhaden and Swansea, the Knights Hospitaller hospices on the pilgrimage routes to Bardsey, the Cistercian infirmary at Strata Florida, and the ysbyty place-names of Ceredigion that preserve the memory of care where every stone has long since gone. Two sites remain unidentified and are recorded honestly as open questions for future research. Each site is GPS-verified and mapped. The survey makes no claim to completeness. There are almost certainly more.