The current position on speech and language intervention for children who have pragmatic language impairment (PLI) is limited by a lack of evidence to support practice. Two intervention outcome case studies of children with PLI, aimed at establishing efficacy, are presented in this paper. Standardized language tests and conversational sampling were used to assess the children pre- and post-therapy. Each child received eight weeks of intervention, three times a week, from a specialist speech and language therapist. This experimental treatment, which was funded as part of a research project, targeted social adaptation skills of the child and adults in his communication environment, in addition to work on communication acts, conversation and narrative skills and facilitating understanding of social inference. One child, with isolated social and pragmatic difficulties, showed measured and reported improvements in conversational skills. The second child, who has additional language disorder, showed changes in language processing skills but no changes in pragmatic abilities. The implications for choosing interventions, for the training of practitioners and questions for further research are discussed. The therapy resources used in intervention are listed. © 2005 Edward Arnold (Publishers) Ltd.