Alongside harm avoidance, incompleteness and disgust have been proposed as important emotion-related motivators underlying the symptoms of obsessive-compulsive disorder (OCD). The aim of the present study was to investigate the validity of self-report and interview-based measures of these constructs in youth with OCD (N=100) and anxiety disorders (N=96). All participants completed self-report measures of trait-level harm avoidance and incompleteness (Obsessive-Compulsive Trait Core Dimensions Questionnaire; OCTCDQ) and a measure of trait-level disgust propensity (Disgust Emotion Scale for Children; DES-C). Participants with OCD were also interviewed about the role that harm avoidance, incompleteness, and disgust played in their moment-to-moment experience of symptoms using a modified version of the Obsessive-Compulsive Core Dimensions Interview (OC-CDI). All measures exhibited theoretically sound factor structures and good internal consistency. Self-report scores for harm avoidance and incompleteness were significantly correlated with scores on the interview-based measure of these emotions in current OCD symptoms. A weaker relationship was observed for disgust. The OCTCDQ, DES-C, and OC-CDI appear to be valid for use with clinically-referred youth, and may be useful when studying the etiology, phenomenology, and course of pediatric OCD. More work is needed to better understand how trait-level aspects of disgust relate to moment-to-moment experiences of disgust in OCD.