Creative self-efficacy has emerged as one of the most striking constructs in education. Yet, instruments to assess it in children and adolescentsare scant. This article introduces the CASES, a new creative self-efficacy scale designed to address this concern. The process of development and initial validation of the scale are presented herein. Following the items’ conception, exploratory, and confirmatory factorial analysis was performed. The final structure comprises nine items, evenly distributed by three factors: fluency, elaboration, and personality. Preliminary reliability and validity analysis display good psychometric properties, highlighting CASES as a potentially relevant addition to the creative self-efficacy assessment instruments array. Designed for children and adolescents (ages 3 to 16), it can uphold a developmental approach of creative self-efficacy, with potential implications within educational settings. Thus, it might be of interest for parents, educators, educational psychologists, researchers, and policymakers involved in designing curricula and interventions to nurture and enhance creative potential.