Background: Communication partner training (CPT) has been shown to improve the communicative environment of people with aphasia. Interaction-focused training is one type of training that provides an individualized intervention to participants. Although shown to be effective, outcomes have mostly been evaluated in non-experimental case studies. Aims: The aim of the controlled experimental intervention study was to evaluate an individualized approach in a CPT programme directed to significant others of people with aphasia. Specifically the effects on conversation partners' ability to support the person with aphasia in conversation and on the individuals with aphasias' perception of their functional communication were explored. Methods & Procedures: Six dyads consisting of a person with aphasia and a significant other were included in a replicated single-subject design with multiple baselines across individuals. The intervention followed the interaction-focused communication training programme included in Supporting Partners of People with Aphasia in Relationships and Conversation (SPARRC). The main elements of the training consisted of supervised viewing of the couples' own video-recorded natural interaction and the formulation of individual goals for the adaptation of particular communicative strategies. Outcome was measured via blinded ratings of filmed conversational interaction obtained once a week throughout the different phases of baseline, intervention and follow-up. A rating scale to assess overall quality of conversation was used, taking into account both transfer of information and social aspects of conversation. Measures of perceived functional communication in the persons with aphasia were also collected from the individuals with aphasia and their conversation partners. Outcomes & Results: The results were mixed, with two of the six participants showing small improvements in ability to support their partner with aphasia in conversation. Half the participants with aphasia and half the significant others reported improvements on perceived functional communication in the person with aphasia after intervention, but no changes were statistically significant. Conclusions & Implications: This study adds to the growing body of research concerning CPT by pinpointing the importance of careful consideration regarding set-up of training, suitability of participants and evaluation of outcome.