Restricted repetitive behaviors (RRBs) are a core feature of autism spectrum disorders (ASD) and further occur in intellectual disability (ID), mental disorders (MD), and in typically developed people (TD). There is a need of a valid and reliable measure to record RRBs as transdiagnostic symptom, which captures RRBs heterogeneity and evaluates severity. The Repetitive Behavior Scale-Revised (RBS-R) is an established screening instrument for RRBs, but was predominantly limited to ASD samples. We examined the psychometric properties of the German version of the RBS-R in 948 participants with ASD, ID, MD and TD aged 4 to 17 years. The suitability was proofed delivering a four-factor solution, good internal consistency, external validity as well as group, age, and sex effects.