The results of an AMS dating programme presented here confirm the attribution of much (and quite likely all) of a large assemblage of human remains from Hay Wood Cave to the earlier Neolithic period. The use of the cave for burial is modelled as commencing in the period 3930-3715 BC and ending 3580-3350 BC (95.4% confidence). While the majority of the 10 dated individuals centre on 3600–3500 cal BC, two are significantly earlier, and indeed represent the earliest directly dated Neolithic individuals from Mendip. Stable carbon and nitrogen isotope data indicate a predominantly terrestrial diet, despite the proximity of the coast, less than 3 km distant. This is consistent with other results from Mendip, and from Britain overall, and provides further support for a rapid and relatively complete dietary transition between the Mesolithic and Neolithic. An intriguing question is what lay behind the decision to place human remains in either a cave or a monument.