The accuracy and reliability of professionals' judgments of the communicative intentionality of acts and behavioral indicators associated with those acts were examined in this study. Twenty special education teachers and 19 speech pathologists were asked to make judgments regarding intentionality and the presence of behavioral indicators for videotaped segments of sequences of behavior for one normally developing child, two children with Down syndrome, and three children with high support needs. Judgments made by these professionals were largely inconsistent with those made by researchers using published criteria, with a tendency to overassign intentionality. Further, judgments were substantially inconsistent both within and between professional groups. Behavioral indicators were more frequently associated with acts judged as intentional by the professionals as compared with acts judged as nonintentional. There was only modest evidence of differentiation of behavioral indicators associated with judgments of intentionality for different types of children. The clinical implications of these findings and directions for future research are suggested.