BACKGROUND: The remediation of pragmatic problems forms a significant part of the caseload for professionals working with children with communication problems. There is little systematic evidence that demonstrates the benefits of speech and language therapy for children whose difficulties lie primarily within the pragmatic domain or which indicates whether changes in pragmatic behaviours, which are a result of a specific intervention, can be measured over time. AIMS: To generate a signal of change in pragmatic and other language behaviours for children with pragmatic language impairments; to gauge the magnitude and nature of the signal and to make recommendations for future studies. METHODS AND PROCEDURES: A case series of six children with pragmatic language impairments without diagnosis of autism received 8 weeks of individual intensive speech and language therapy supported in a mainstream educational setting in the UK. Measures of pragmatic behaviours in conversation were made at seven data points before and after therapy using Bishop's ALICC procedure. Conversation coders were blind to the point of assessment. Inferential comprehension, narrative, sentence formulation and sentence recall skills were also tested before and after therapy. The opinions of teachers and parents were sought regarding any change in communication and social abilities of the children over time OUTCOMES AND RESULTS: All children showed change in communication behaviour on some conversational measures, even if the child functioned at the ceiling on standardized language testing. Some conversation measures had more utility as outcome measures than others. Most children showed substantial change on standardized language measures, but there are limitations on the use of these due to heterogeneity within the group. Overall, the intervention produced a signal for change in pragmatics and/or language behaviour in all children. Parent/teacher opinion reported demonstrable change in communication behaviour and engagement in the curriculum. CONCLUSIONS: There is a strong signal that change in pragmatic language behaviour can be measured in well-controlled intervention studies but this signal is complex. Outcome measures should take into account changes in language processing skills that are significantly impaired in many children with PLI. For those children within the PLI group who function at ceiling on language tests, conversational measures may have the potential to signal change, but this finding has not been subjected to group study or to testing in generalized settings. Qualitative data regarding behaviour, classroom engagement and generalization of language gains will be an essential supplement to measuring progress in a diverse population.