Dental enamel is the hardest tissue of the mammalian body, consisting of 96–98% inorganic compound. As the dentition is functionally adapted to diet and feeding behaviour, relative differences in enamel thickness can reflect dietary adaptations. We hypothesize that differences in enamel thickness are related to adaptation for diet associated with habitat quality dwelling of European roe deer Capreolus capreolus. To test this hypothesis, 49 first permanent left lower molars were extracted from the mandible of roe deer (from Lithuania – 28 and Poland – 21 molars) inhabiting two type of habitats: field and forest. The linear thickness of total enamel (mean value of enamel thickness measured at three different points) was found to differ between the roe deer from the field and forest habitats, irrespective of age, with the animals of field ecotype tend to have thinner enamel (F_(1,26) = 6.845, P = 0.025). This suggests that there is an adaptation in enamel thickness to various types of diet in the field and forest habitat. On the other hand, roe deer from the field habitat can be also more exposed to stress, due to the lower possibility to hide or are more vulnerable to potential threats. More frequent exposure to stress can significantly disrupt ameloblasts secretion and thus affect the thickness of the enamel.