Objectives: Dietary antioxidant intake decreases the risk of many diseases. Hyperemesis gravidarum (HG) is the most common eating disorder during pregnancy. Therefore, the authors conducted this prospective and case control study to evaluate dietary antioxidant levels of women with HG and compare with healthy pregnant women. Material and Methods: This prospective case control study was conducted at a government hospital in the southeastern region of Turkey, from February 2010 to May 2010. A total of 100 pregnant women were included into the study. Dietary antioxidant levels (DAL) were measured according to the new 92-item antioxidant nutrient questionnaire developed by Satia et al (1). 50 women with HG and 50 healthy pregnant women were evaluated. Statistical analyses were carried out with statistical packages for SPSS 15.0 for Windows (SPSS Inc., Chicago, IL, USA). Results: There were no statistically significant differences between the groups regarding the age of the patients, gestational age, educational status, body height and weight (p>.05). Vitamin E, E equivalent, vitamin C, carotene and vitamin A levels were significantly lower in women with HG (p<.05). The results of logistic regression method for these variables including odds ratio (95 % CI) were as follows: 10.07(1.52-66.51), 7.37(2.66–20.41), 4.26(2.66–20.41), 3.66(2.38–5.63) and 2.75 (1.56–4.85), respectively. Conclusion: According to this study, vitamin E, E equivalent, vitamin C, carotene and vitamin A levels of women may play a role in the pathogenesis of HG. Therefore, diet recommendations should be given by clinicians before pregnancy.