In recent years, plant-based nutrition has become a current topic, together with movements for animal rights and for the promotion of healthy eating, with which it is closely related. The term "plant-based diet" refers to several classifications of diets and food choices, such as vegetarian, vegan, semi-vegetarian, lactovegetarian, ovo-vegetarian, pescatarian, or flexitarian. The reasons for switching to this type of diet can be classified into three categories: concern for the preservation of the environment, concern for animal rights, and concern for health. Previous research has established a connection between vegetarianism and empathy towards animals and orthorexia nervosa. The aim of this research was to include all three variables and to examine the differences in orthorexia behavior and empathy towards animals between vegetarians and omnivores, as well as between men and women, and the connection between orthorexia and empathy towards animals. 264 subjects participated (204 women and 60 men). An online questionnaire was administered, which consisted of a sociodemographic questionnaire that included a question about type of diet, the Empathy Scale for Animals, and the Orthorexia Nervosa Inventory. Analyzing the results, it was determined that vegetarians empathize more with animals and have more indicators of orthorexic behavior compared to omnivores and that women have more indicators of empathizing with animals compared to men, but there is no difference in orthorexic behavior between men and women. No significant correlation was found between empathy towards animals and orthorexia nervosa, except in the group of vegetarians where vegetarians who are more empathetic towards animals had fewer indicators of orthorexia behavior.