The Emotion Dysregulation Inventory (EDI) was designed and validated to quantify emotion dysregulation (ED) in school-age children, with a particular emphasis on capturing ED in youth with ASD. We saw a need to adapt the EDI for use in young children (ages 2–5) given early childhood is a formative time for emotion regulation development. The present study discusses the adaptation process for the EDI-Young Child (EDI-YC), including item refinement/generation and cognitive interviews (N = 10 with ASD), consistent with the Patient-Reported Outcomes Measurement Information System (PROMIS®) methodology. The item bank was piloted in a sample of 2-year-olds with and without ASD (N = 31), which provided initial support for the EDI-YC as a valid and reliable measure.