The Mindful Eating Questionnaire (MEQ) was constructed as a tool to measure mindfulness in eating behavior. This chapter outlines and evaluates the MEQ and its initial validation as an instrument to self-report mindful eating. Mindfulness and eating behaviors have often been two very separate fields of study, and this chapter examines how the theory from two such disparate fields has been brought together to form the theoretical foundations to scale development. The 28-item MEQ was based on the theoretical constructs developed by Jon Kabat-Zinn and initially validated with yoga practitioners and individuals engaged in physical activity and weight-loss programs. Exploratory factor analysis revealed five factors comprising domains of the MEQ: disinhibition, awareness, external cues, emotional response, and distraction. The MEQ differentiated cognitive restraint behaviors from mindful eating, which is a valuable contribution to the field. The MEQ has been used in a range of psychometric research projects from educating individuals on mindful eating to addressing serious eating disorders and related factors. The MEQ has also been validated cross-culturally in a range of different countries and languages.