A group of five preschool children with developmental disability and their mothers participated in a study into the efficacy of a parent-implemented language intervention. Each parent was included in the team as a consultee, with a speech pathologist and special educator acting as consultants within a collaborative consultation process. Treatment for each child was developed using this process, with specific strategies to increase language production skills decided by the team. Strategies were used within an interactive model of early language intervention. The effectiveness of treatment was determined within a multiple baseline design. For three children, the impact of treatment was evident, but the results were not replicated for the other two children. Descriptive analysis of mothers' communicative behaviours indicated that, following treatment, they tended to direct more utterances to their children, used more models, fewer questions and directives, and more (although limited) teaching strategies.