Anxiety continues to be one of the most frequent disorders with typically developing children and youth. However, people with intellectual disability (ID) lack validated diagnostic tests backed by sufficient methodological rigor. Analyze the psychometric properties of the Screen for Child Anxiety Related Emotional Disorders (SCARED) in this clinical population, specifically in children and young Spanish with Nonspecific Intellectual Disability. Descriptive statistics and item analysis (N = 542), exploratory factorial analysis (n = 245) and confirmatory (n = 297) and scale reliability analyses were performed and evaluated the internal consistency with various indices (Cronbach’s alpha and omega) and the stability of the measurement (test–retest) of the resulting scale with better goodness-of-adjustment indices. A new scale called SCARED-DI was obtained in this clinical sample with three factors and a smaller number of items (22), offering important goodness-of-fit indices (RMSEA [95% CI] 03[0.01; .04]; CFI = 0.99; TLI = 0.98; GFI = 0.88; AGFI = 0.89) and high internal consistency (α = 0.91; ω = 0.93) and adequate measurement stability (rxx = 0.92). The importance of validating psychopathological anxiety tests for children and youth with ID in order to build good mental health is discussed, emphasizing the need to provide easy, short-duration tests on both cognitive and emotional aspects in this clinical sub-population. In addition, the results are assessed in terms of future research and practical implications. This new version of SCARED-ID represents a valid and reliable tool to evaluate the anxiety in people with intellectual disabilities.