Background: Discourse analysis as a clinical tool in speech and language therapy remains underused, at least partly because of the time-consuming nature of the process of transcription that currently precedes it. If transcription-less discourse analysis were valid and reliable, then there would be the clinical opportunity to use this method in order to describe a person's communication impairment (for example aphasia), to help plan therapy and to measure outcomes. Aims: This study aimed to address the potential of transcription-less discourse analysis as a valid and reliable procedure for the measurement of gesture use, topic use, turn taking, repair, conversational initiation, topic initiation, and concept use. Methods & Procedures: Ten individuals with aphasia were audio- and video-recorded participating in a number of discourse tasks from three different discourse genres (conversation, procedural, and picture description). With the same analytical frameworks, the resulting data were compared using transcription-based discourse analysis and a transcription-less method in which the analysis was made directly from the recordings. Outcomes & Results: Validity was measured by comparing transcription-based and transcription-less analyses. Overall the results from that comparison demonstrated the potential of the latter method - none of the measures gave significant differences between scores from the two methods. The main (non-significant) disparities related to some aspects of gesture use and repair. The inter-rater reliability of the transcription-less method was also acceptable in general. Reliability was measured by the intraclass correlation coefficient (ICC) for the continuous measurements: it was strongest for the gesture totals and varied among the attributes of turn taking and repair. For the categorical measures (topic and conversation initiation and concept analysis) the percentage agreement was very good. Conclusions: These results indicate the potential availability of a valid and reliable transcription-less approach to analysis that speech and language therapists can apply to analyse their clients' discourse.