© The Authors 2021.Objectives: Obesity is a serious public health issue. Investigating the eating behavior of individuals plays an important role in preventing obesity. Therefore, the purpose of this study is to adapt the long and first version of the 'Three-Factor Eating Questionnaire' (TFEQ), a scale that examines the eating behavior of individuals, to Turkish culture and to carry out its validity and reliability study. Design: The data were collected using data collection forms, and anthropometric measurements of the individuals were made by the researchers. The data collection form included several parameters: sociodemographic characteristics, the TFEQ scale-whose validity and reliability analysis is conducted here-, and the Dutch Eating Behavior Questionnaire (DEBQ) which was used as a parallel form. Setting: The Obesity Clinic at Ege University in Izmir. Participants: The study group consisted of obese adult individuals (n=257). Results: It was seen that constructing the questionnaire with 27 items and four sub-dimensions provides better information about Turkish obese individuals. Factor loadings ranged from 0.421 to 0.846, and item total score correlations ranged from 0.214 to 0.558. Cronbach's alpha coefficient was found to be 0.639 for the whole scale. A positive, strong, and statistically significant correlation was detected between TFEQ and DEBQ, which was used as a parallel form (r = 0.519, p <0.001). Conclusion: In Turkey, the long version of the TFEQ scale was found valid and reliable for obese adult individuals. TFEQ can be used by clinicians or researchers to study the eating behavior of obese individuals.