Two samples of bone from Tyning’s Great Swallet were submitted for accelerator radiocarbon dating. The dates obtained, at 95.4% probability, were: 2480 - 2290 BC for Bos primigenius from about 40 m depth and 400 - 340 BC (34.8%) ; 300 - 200 BC (60.6%) for Homo sapiens from about 30 m depth. These results imply that the infilling of this shaft was a relatively gradual and probably natural process. In the absence of Iron Age artefacts, the circumstances of the deposition of the human remains are obscure.