Total Communication is a collaborative intervention approach delivered by teachers and speech and language therapists (SLTs) to support children with complex speech language and communication needs (SLCN). Total Communication combines the intervention approaches of active learning and support for speech using augmentative and alternative communication (AAC). The AAC consists of signing, and the use of voice output communication aids / speech generating devices (VOCAs / SGDs) and communication boards. This study reports on the evaluation of the effectiveness of this approach to support primary age children with complex SLCN. The study aims to determine if the collaborative Total Communication approach facilitates communication ability. The following questions are asked: does the Total Communication approach increase the communication ability (mean length of utterance, and number of propositions, using any communication mode) of pupils with severe and complex SLCN? Is conducting an evaluation study of a holistic Total Communication approach using single case experimental design (SCED) in a special school context effective? A multiple probe design across participants was used to evaluate Total Communication with three children between 8 and 10 years. Following baseline, the children took part in the Total Communication intervention in a story telling context, via class-based active learning with speech, signing and VOCAs plus communication boards. Probes measured the children's subsequent story re-telling with these communication modes. All participants showed increases in their production of propositions and the mean length of their longest utterances, using a variety of modes of communication. Gains were sustained and generalised. The study shows Total Communication is effective in increasing the communicative ability of children with complex SLCN.