Objective To identify vegetarianism prevalence and associated factors among students at a public university in Southern Brazil. Methods This was a cross-sectional study carried out in 2017-2018 with first-year university students. A questionnaire was administered to assess diet type (omnivorous or vegetarian). Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95%CI). Results Of 2,706 eligible individuals, 1,841 formed part of the sample. The predominant type of diet was omnivorous (93.6%), followed by lacto-ovo vegetarian (5.4%), strict vegetarian (0.7%), ovo vegetarian (0.2%) and lacto vegetarian (0.1%). Females (OR=0.58 - 95%CI 0.38;0.89), students reporting harmful use of alcohol (OR=2.02 - 95%CI 1.34;3.04) and students enrolled in Linguistics, Modern Languages and Arts courses - compared to those enrolled in Applied Social Sciences and Humanities courses (OR=2.59 - 95%CI 1.42;4.71) - were more likely to be vegetarians. Conclusion Vegetarian diet was associated with the female sex, alcohol use, and taking linguistics, modern language and arts courses.