A brief multidimensional measure of adult picky eating (PE) behavior was developed using a large U.S. adult sample. In addition, the study explored associations between specific aspects of adult PE behavior and psychosocial impairment in effort to support the inclusion of adults in the Diagnostic and Statistical Manual for Mental Disorders-Fifth Edition (DSM–5) avoidant-restrictive food intake disorder (ARFID). The study included 3 phases of qualitative and quantitative data collection. Participants were 1,663 U.S. adults who completed online surveys. Exploratory and confirmatory factor analyses were used to develop PE subscales. Associations among the PE subscales and measures of psychosocial impairment were examined. Exploratory and confirmatory factor analysis supported a 16-item 4-factor model of adult PE that included subscales of meal presentation, food variety, meal disengagement, and taste aversion. The measure also demonstrated convergence with previous measures of PE. The meal disengagement and meal presentation subscales demonstrated significant associations with social eating anxiety, anxiety sensitivity, eating related quality of life (QOL), and psychological flexibility. Meal disengagement alone was significantly associated with depressive symptoms. The Adult Picky Eating Questionnaire (APEQ) demonstrated sound psychometric properties and may be used to further investigate adult PE behavior. The relationships between adult PE and psychological impairment, particularly social anxiety, support the inclusion of ARFID in the DSM–5.