Objective: The purpose of this study was to evaluate the reliability and validity of Turkish Version of the Night Eating Questionnaire (NEQ) in psychiatric out-patient population as a measure of severity of the night eating syndrome (NES). Methods: We examined the factor structure, internal consistency and validity of the NEQ in Turkish. First, we translated NEQ into Turkish and than back-translation into English; correction and semantic adaptation and assessment of the understanding of the questionnaire. We made the diagnosis of NES according to psychiatric examination. We administered the NEQ in 433 patients and the re-test in 141 participants two weeks later. Result: The instrument showed satisfactory internal consistency with an overall Cronbach a of 0.69. Intradass correlation for the test re-test total score was 0.96. The ninety seven patients had NES with psychiatric examination. The area under ROC curve defined as 0,904. For cuff-of point of 18 in NEQ both sensitivity and spesificity were as 90.7% and 73.8%. The confirmatory factor analysis of the NEQ yielded a similar four factor solution as the original scale. Conclusions: We found that Turkish version of NEQ is valid and has good diagnostical performance, and high internal consistency.