The purpose of this study was to translate the Night Eating Diagnostic Questionnaire (NEDQ), developed (2001) and revised (2016) by Nolan et al., into Korean and to test its validation. After translating it into Korean, the NEDQ was distributed to 766 individuals, and 60 of the subjects took a test-retest with an interval of four weeks between the tests. The retest reliability coefficient was good. Correlation analysis was conducted to examine its correlations with the Korean Version of the Night Eating Syndrome Scale, which had been already developed in Korea, to test its validation. The analysis results showed significant correlations. Also, the NEDQ had significant correlations with negative urgency, depression, binge eating, BMI, and eating expectancy. Since previous studies on eating disorders reported higher prevalence in women, the present study analyzed gender differences on the NEDQ to see whether such differences would also be found on the Night Eating Syndrome Scale. Female college students scored significantly higher on average than their male counterparts. Male college students, however, scored higher than females on negative urgency, eating expectancy, and binge eating in cases of serious Night Eating Syndrome; this is because men have insensitive attitudes toward their eating behavior and negative urgency, thus neglecting these and reaching serious levels. The present study is significant in that it conducted validation research on the Night Eating Syndrome Questionnaire in Korea, providing a clinically useful instrument. In addition, it checked the clinical influence of psychological traits contributing to the syndrome, offering specific interventions to individuals with the issue of repeating night eating.