Adolescents with language impairment frequently experience difficulties with story- telling tasks and the development of their story-telling or narrative abilities differ from those of typically developing young people. In this study a dynamic assessment and intervention approach was used to assist the development of narrative abilities of secondary-aged pupils with language difficulties. The initial phase of the study involved eliciting narratives from pupils using a wordless picture book. This was followed by two individually administered mediated learning experiences over a two-week period. Pupils' narratives were elicited and scored following this. The second phase involved small, group mediated teaching of narratives over a ten-week period at the end of which pupils' narratives were retested. Sixtysix pupils across four secondary schools participated in the study and were assigned to either an experimental or a control condition. A two-phase, sequential, mixed methods design incorporating both a within and a between subjects design using a test-mediate-retest method within a dynamic assessment paradigm was employed. Pupils' views were obtained through three focus groups. The views of the professionals involved in the intervention were obtained through post-intervention reflective sheets. A conventional content analysis that adopted a constructivist paradigm was used to analyse the data from the focus groups and the reflective sheets. A highly significant improvement was found in both the qualitative and quantitative aspects of the intervention group's narratives following the dynamic assessment and intervention phase and the group-mediated teaching sessions. However, a within-group analysis showed a slight decline in the quantitative but not the qualitative narrative measures following the group mediated teaching of narratives. The pupils in the intervention group also showed significant gains in their narrative performance on a standardised test of narrative ability following the group mediated teaching of narratives. A surprising result was that pupils in the control group showed a five percent improvement in the qualitative but not the quantitative aspects of their narratives. Pupils and professionals reported an increased awareness and understanding of the importance of narratives and the inclusion of aspects that made up a complete narrative. Pupils reported on how particular mediation strategies had helped them with their story telling while professionals reported an increased understanding of a mediated teaching approach. Pupils and professionals reported an increase in confidence and expressed a need to link the mediated teaching of narratives to class-work and monitoring systems used in school. In spite of the study's limitations, the results showed how the narrative abilities of secondary-aged pupils with language difficulties could be developed through a dynamic assessment and intervention approach enabling pupils to become active learners.