Orthorexia is a new term about eating behavior disorder and consists of pathologic obsession for biologically pure foods, free of herbicides, pesticides, and other artificial substances. It is not an independent diagnostic category, but it has some similarities with other eating disorders. This study was conducted to examine the orthorexia among 878 medical students. Of 878 students, 464 (52.8%) were male and 359 (40.9%) were female. The mean age, height, weight, and body mass index were 21.3 +/- 2.1 years, 171.0 +/- 8.5 cm, 65.6 +/- 12.3 kg, 22.4 +/- 2.99, respectively. The rates of the ORTO-11 scores between 0 and 15 was 1.9%; between 16 and 30, 57.5%; and between 31 and higher, 21.1%. There were 17 students with a score of 0 to 15. The mean score for the ORTO-11 test was 27. There were statistically significant differences between age, sex, and smoking habit of the students. In the male students, there was a statistically significantly higher tendency for orthorexia (P = .001), and there was a statistically significant difference between the age groups for tendency for orthorexia (P = .025). In logistic regression analysis, age, sex, Eating Attitude Test-40 (EAT-40), and height affected the ORTO-11 scores.