BACKGROUND This study aimed to evaluate the knowledge and attitudes of 4th- and 5th-year students of Dicle University Faculty of Dentistry (Diyarbakır) about molar incisor hypomineralization (MIH). MATERIAL AND METHODS The questionnaires previously used in other countries were modified and the questionnaire forms consisting of 23 questions were distributed to the students online. The results of the analysis are presented as frequencies. The significance level was set as P<0.05. RESULTS A total of 111 4th-year students (51%) and 107 5th-year students (49%) participated in our study. A statistically significant difference was found between the 4th-year students (68.5%) and the 5th-year students (98.1%) in terms of having heard of the term MIH before (P<0.001). While most students reported knowing the clinical features of MIH, only 26.1% were confident in their diagnosis. A statistically significant difference was found between the 4th- and 5th-year students who thought that MIH was a clinical problem, in the distribution of those who had problems both in terms of aesthetics, and in providing adequate restoration (P=0.012). CONCLUSIONS Although most of the students were theoretically familiar with MIH, they were not confident in their diagnosis and found it difficult to differentiate MIH from other dental anomalies. However, the awareness of 5th-year dental students was better than that of the 4th-year students.