PURPOSE:Little is known about the critical ingredients of successful Communication Partner Training (CPT) programmes. The aim of this randomised controlled trial was to investigate the effects of including an educational component before a conversation with a person with aphasia compared to a conversation only. METHOD:Thirty-eight speech-language pathology students were randomly allocated to either the Full programme or Conversation only groups. The Full programme group received a lecture about communication strategies then participated in a conversation with a person with aphasia, while the other group participated in the conversation only. Both groups received feedback on performance from the people with aphasia. Students completed a customised mixed-methods questionnaire at study commencement and following the conversation. RESULT:Generalised linear models indicated confidence ratings improved after receiving either the Full programme or Conversation only (p < 0.001), however, greater improvements were observed following the Full programme (p < 0.001). More communication strategies were identified after the interventions (p = 0.001) with greater improvement occurring among the Full programme group (p < 0.01). CONCLUSION:An educational lecture before a conversation with a person with aphasia is a critical component of CPT programmes, enhancing their knowledge base and increasing their confidence levels compared to only a conversation.