Disruptive behavior problems among young children can result in long-term negative consequences, highlighting the importance of early interventions. While there have been recent developments in early interventions (e.g., Parent–Child Interaction Therapy-Toddler), there is a need for brief assessments for toddler disruptive behaviors. The current study aims to adapt the Eyberg Child Behavior Inventory (ECBI) for toddler-aged children. Archival data from toddler- and preschool-aged children underwent a three-step process for data reduction (qualitative content validation, missing data and low variability exclusion, and criterion-related validation against the preschool version of the Child Behavior Checklist [CBCL]). Exploratory and confirmatory factor analyses with measurement models on the reduced item set were conducted, with a final validation model against the CBCL. This procedure resulted in eight of the 36 items of the ECBI being retained. A metric measurement model of the 8 items, allowing for higher average scores for preschool children compared to toddlers, fit well (chi-square p = 0.13; SRMR = 0.07, GFI = 0.98, NFI = 0.94). This study provides evidence for a developmental factor of the ECBI for toddler-aged youth that can be used in future clinical and research work. Items included on this factor support previous research that suggests toddler behavior problems are partially due to undeveloped emotion regulation skills and parent–child attachment concerns.