The Behavioral Summarized Evaluation scale (BSE), previously published and validated, was developed for the evaluation for the autistic behavior in developmentally disorder children. A revised version of this scale, the Revised Behavior Summarized Evaluation Scale (BSE-R) completed the 20-item BSE scale with the most relevant items extracted from a similar evaluation carried out with very young children. Thus 9 items were added to the original scale concerning nonverbal communication, emotional, and perception areas. This paper reports the reliability and validity studies of this new scale. In addition to confirming the previously published findings concerning the first version of the BSE, new items were extracted from the BSE-R content validity study. They involve fundamental functions such as intention and imitation which open new perspectives for a physiopathological approach to developmental disorders. The BSE-R is a useful tool for progressive recording of the evolution of patients both treated over long periods and included in short-term controlled therapeutic studies.