["International Journal of Osteoarchaeology, Volume 36, Issue 2, Page 401-413, March/April 2026. ", "\nABSTRACT\nPrior research has documented treponematosis at a single site in Mainland Southeast Asia from northern Vietnam dated to the early agricultural transition (~4000–3500 bp). To date, no other cases in Southeast Asia's prehistory have been identified. Here, we present evidence for congenital treponematosis in three non‐adults from two different sites in north and south Neolithic Vietnam (4000–3200 bp) who present with dental and/or skeletal evidence consistent with congenital treponematosis, including Moon's molars of the deciduous and permanent dentition, gummatous lesions, saddle nose, and goundou. Following an extensive review of clinical and paleopathological literature, we provide here a new threshold approach for dental stigmata related to congenital transmission of treponematosis. No other cases of treponematosis (congenital or acquired) were found in Vietnam following an extensive analysis of archaeological assemblages dated from 10,000 to 1000 bp (n = 309), suggesting treponemal disease was not a widespread condition on the east coast of Mainland Southeast Asia in prehistory. These findings also indicate a deep plasticity of Treponema pallidum, as the broader epidemiology still indicates a non‐venereal form of the disease in Vietnam's prehistory, even with the evidence of congenital transmission.\n"]