Purpose: Evidence exists which suggests that a vegetarian diet is a predisposing factor to erosive tooth wear. The aim of this study was to assess the influence of dietary pattern (vegetarian, lacto-ovo vegetarian and omnivore) on erosive tooth wear. Materials and Methods: Two hundred seven subjects (29 vegetarians, 96 lacto-ovo vegetarians and 82 omnivores) underwent an oral assessment and were asked to answer questionnaires about diet and oral care. Results: Individuals who followed vegetarian and lacto-ovo vegetarian diets had statistically significantly more erosive tooth wear than did omnivores (p = 0.004). Conversely, omnivores presented more tooth loss than did lacto-ovo vegetarians (p = 0.027). Being a vegetarian or a lacto-ovo vegetarian entailed an increased risk (4 times and 2.5 times, respectively) of presenting erosive tooth wear than being omnivorous. Conclusion: Vegetarian and lacto-ovo vegetarian dietary patterns seem to favour the loss of dental structure by erosion. Vegetarian patients should thus be informed about preventive measures and treated accordingly. Keywords: diet, food habits, oral health, vegetarian