There is growing recognition of the communicative potential in many of the informal and idiosyncratic behaviors exhibited by children with developmental and physical disabilities. To assist in assessment and intervention planning, it would seem important to identify these potential communicative acts. To this end, the present article describes the development of the Inventory of Potential Communicative Acts (IPCA). The IPCA is an interview schedule designed to be completed by parents, teachers, and therapists of children with developmental and physical disabilities and severe communication impairment. It consists of 53 questions asking informants to indicate how the child communicates 10 distinct pragmatic functions. To date, pilot testing, development research, and field trials have involved 30 children. The results of this development work indicate that the IPCA is an efficient means of collecting accurate and verifiable data on the potential communicative acts of children with severe communication impairment associated with a range of developmental and physical disabilities. Use of the IPCA in communication assessment and intervention is discussed.