Background: The outcomes of a pilot program of staff development in communication support in the context of observed changes in student behaviour states and interactive abilities are reported. Participant reports about the impact of the program on their professional practices are included. Method: Six teachers and six teacher aides in special (segregated) schools were provided with a short, intensive training program designed to improve their communicative interactions with students with multiple and severe disability (MSD) in their classes. Behaviour state assessment was used for pre- and post-testing of six students. Teachers and aides completed self-report scales related to their communication skills, knowledge and concerns prior to and at the conclusion of the training program. Results: While staff reported improved skills and knowledge, this was not reflected in improvements in the communicative interactions of the students as observed in their classrooms. Conclusions: The training provided may not have been sufficient to change well-established teaching and interaction processes. Further research using in-school collaborative mentors is planned. (Contains 5 tables. Codes and Definitions for Behaviour State, Communication, Social Context and Curriculum Areas are appended.) [This paper was developed from a presentation made to the "International Special Education Congress," Glasgow, June 2005. This paper was produced by Taylor and Francis Ltd. Philadelphia, PA.]