Parental overprotection is thought to be a risk factor for childhood anxiety disorders. The Parental Overprotection Measure (POM) is a self-assessment scale that has been used in many studies, however, no article has comprehensively explored its psychometric properties. The aim of this study was to evaluate the POM to secure reliable, replicable, and comparable results. Using an item-response theoretical framework, we aimed to address five basic criteria of psychometric quality: one-dimensionality, ordered response categories, invariance, targeting, and reliability. Furthermore, we aimed to identify and exclude any items that did not contribute significantly, to create a concise and practical scale. A total of 1092 parents of children aged 4–12 years were recruited through an online advertisement and completed an anonymous online survey during September and October 2020. Out of the 19 items of the original scale, eight were excluded due to unsatisfactory psychometric properties and/or because of not being judged by experts as harmonious with the concept of parental overprotection. The retained items constituted the POM-11, a brief scale with sound psychometric properties that has the potential for use in both research and clinical settings.