We present radiocarbon dates, stable isotope data, and osteological analysis of the remains of a minimum of 17 individuals deposited in the western part of the burial chamber at Coldrum, Kent. This is one of the Medway group of megalithic monuments – sites with shared architectural motifs and no very close parallels elsewhere in Britain – whose location has been seen as important in terms of the origins of Neolithic material culture and practices in Britain. The osteological analysis identified the largest assemblage of cut-marked human bone yet reported from a British early Neolithic chambered tomb; these modifications were probably undertaken as part of burial practices. The stable isotope dataset shows very enriched δ15N values, the causes of which are not entirely clear, but could include consumption of freshwater fish resources. Bayesian statistical modelling of the radiocarbon dates demonstrates that Coldrum is an early example of a British Neolithic burial monument, though the tomb was perhaps not part of the earliest Neolithic evidence in the Greater Thames Estuary. The site was probably initiated after the first appearance of other early Neolithic regional phenomena including an inhumation burial, early Neolithic pottery and a characteristic early Neolithic post-and-slot structure, and perhaps of Neolithic flint extraction in the Sussex mines. Coldrum is the only site in the Medway monument group to have samples which have been radiocarbon dated, and is important both for regional studies of the early Neolithic and wider narratives of the processes, timing, and tempo of Neolithisation across Britain