In emotional eating (EE), affective states influence desire to eat and/or eating behavior. Most research on EE focuses on over-/under-eating in response to negative emotions, the former of which is related to higher weight and binge-spectrum eating disorder (ED) symptoms while the latter has been implicated in low weight and restrictive-only ED. Individuals endorsing both forms of negative EE are more impaired than those reporting unidirectional negative EE. Less is known about the influence of positive emotions on eating, in part due to a lack of self-report measures of positive over- and under- eating as separate constructs. The current study presents the development, including item reduction and initial factorial validity (primary aims) and convergent validity (secondary aims) of the Comprehensive Emotional Eating Scale (CEES), a four-factor measure of positive and negative over- and under-eating. The initial 134-item pool for the CEES was based on a review of extant emotional eating scales and emotion words from the Positive and Negative Affect Schedule. The item pool was reduced and four factors identified using exploratory graphical analysis. The structure of the final set of 40 items was evaluated using confirmatory factor analysis. Convergent validity of the negative over- and under-eating scales was established using measures of body image-focused eating disorder and ARFID symptoms, and exploratory data on the correlates of positive over- and under eating were reported. The CEES showed preliminary evidence of factorial and convergent validity in a US-based convenience sample. It allows for classification on all four quadrants of emotional eating.