This paper presents 28 AMS 14C determinations and associated stable carbon and nitrogen isotope measurements on human bone primarily from cave contexts in Wales, with a small number of additional cave and non-cave contexts in southwest England. While some of these dates have been previously published, the entire series was originally affected by a problem with the ultrafilters in use at the Oxford radiocarbon dating laboratory where they were analysed. The original dates were consequently all withdrawn in 2007, and for most new measurements have been made. The project was originally focussed on identifying Mesolithic and Neolithic human remains from Welsh caves in order to provide a chronological framework for an isotopic investigation of diet, and for the temporality of the use of caves for burial. Thus, the majority of the results reported here date to the Mesolithic and Neolithic, though human remains are also identified from the Bronze Age, Iron Age, and Romano-British periods. The results confirm the previously observed sharp shift towards the dominance of terrestrial foods in coastal locations at the start of the Neolithic, as well as supporting the use of caves for the deposition of human remains in the earlier Mesolithic and in the Neolithic, separated by an intervening gap of nearly two millennia suggesting no meaningful continuity in the practice.