Updated project metadata. Human skeletal tissue contains an abundance of proteins some of which may be preserved over geological timescales. The profiling of proteins from ancient individuals — or palaeoproteomics —has begun to provide new information about the diseases suffered in past societies. We describe here the first dental palaeoproteomic profiles of Iron Age individuals, collected from the site of Long Long Rak rockshelter in northwest Thailand. We recovered amino acid sequences for thousands of proteins preserved in their dental tissue, however, it is evident that these palaeoproteomic profiles comprise a palimpsest of modifications that occurred both ante-mortem and post-mortem. Palaeoproteomic profiles are able to categorise disease and show the capacity of these individuals for harboring a variety of illnesses prior to death. Here we apply for the first time palaeoproteomic analysis to five prehistoric human teeth from Southeast Asia. We combine this method with stable isotope analysis using δ18O and δ13C values to broadly identify the diet of these individuals. The specimens were collected from log coffins contained within the Iron Age site of Long Long Rak (LLR) rockshelter in Pang Mapha district, Mae Hong Son Province, northwest Thailand.. Radiocarbon dating shows these log coffins to date within the range of 1,960±30 cal. yr BP to 1,636±44 cal. yr BP.