"Mindful eating" describes a nonjudgmental awareness of physical and emotional sensations associated with eating. This article reports the development of a mindful eating questionnaire (MEQ) to support rigorous scientific inquiry into this concept. An item pool was developed based on hypothesized domains of mindful eating. A cross-sectional survey examined associations of MEQ scores with demographic and health-related characteristics. The MEQ was distributed to seven convenience samples between January and May 2007, with an overall response rate of 62% (n=303). Participants were mostly women (81%) and white (90%), and had a mean age of 42+/-14.4 years (range 18 to 80 years). Exploratory factor analysis was used to identify factors, which were defined as the mean of items scored one to four, where four indicated higher mindfulness; the mean of all factors was the summary MEQ score. Multiple regression analysis was used to measure associations of demographic characteristics, obesity, yoga practice, and physical activity with MEQ scores. Domains of the final 28-item questionnaire were: disinhibition, awareness, external cues, emotional response, and distraction. The mean MEQ score was 2.92+/-0.37, with a reliability (Chronbach's alpha) of .64. The covariate-adjusted MEQ score was inversely associated with body mass index (3.02 for body mass index <25 vs 2.54 for body mass index >30, P<0.001). Yoga practice, but neither walking nor moderate/intense physical activity, was associated with higher MEQ score. In this study sample, the MEQ had good measurement characteristics. Its negative association with body mass index and positive association with yoga provide evidence of construct validity. Further evaluation in more diverse populations is warranted.