Dropout is a significant concern for providers and researchers of adolescent psychotherapy due to the potential impact on resources and outcomes. Some of those who dropout, do so as they are dissatisfied with their treatment, however there is little research into the therapeutic processes that precede dissatisfied dropout. The aim of this single-case study was to further our understanding regarding the interactional processes that are implicated in a therapy where the client dropped out and remained dissatisfied with the treatment. The case was sampled from a wider sample of ‘dissatisfied dropouts’, previously identified as participants in the IMPACT study, who had dropped out from treatment and were dissatisfied with their treatment. Sessions were transcribed verbatim and analysed using discourse analysis. The findings identified specific actions the therapist took to attempt to construct the young person’s problem as psychological in nature, which the young person most often rejected. Over the course of therapy, the young person’s response shifted from an implicit to an explicit communication of rejection. These results demonstrate the way in which initial rejection of the therapist’s construction may be an indicator of upcoming ‘dissatisfied dropout’ and suggestions for further research include investigating whether ‘dissatisfied dropout’ can be reduced through adaptation of technique.