A skeleton of an approximately 3-years-old sub-adult, in an excellent state of conservation, was found at the Pedra do Cachorro rock shelter -Buíque, Pernambuco -Brazil, an archaeological site used as funerary place between 3875 and 575 cal years B.P. The skeleton has no signs of pathological bone changes, but its maxillary teeth show strong evidence of enamel and dentin wear caused by acid erosion, suggesting vomiting or gastroesophageal reflux episodes. The aim of this study was to describe the lesions and discuss the aetiology of these dental defects with the emphasis on the cause of the death of this individual.