The objective of this research is to investigate the effectiveness of an intervention in terms of reflective function, the ability to mentalize, and integration of emotions. Mentalization is about understanding behaviour in terms of underlying thoughts, feelings and intentions and is intrinsic to human well being and at the heart of attachment theory. Mentalization is also crucial to affect regulation and productive social relationships. Art in psychotherapy has many features associated with reflective functioning. From family therapy, genogramming illuminates family patterns and processes that operate implicitly, outside conscious awareness. Using a qualitative approach this study examined therapists‟ experiences during genogramming to explore aspects of mentalization.. Using a thematic analysis of transcripts from a semi-structured interview, four super-ordinate themes emerged: 1) I thought I knew; 2) Unconscious processes; 3) The power game; 4) Integration. Results showed that perspectives changed for the participant therapists and their clients, a key feature of reflective functioning. Access to affect was also reported in relation to some clients however the appearance of defence mechanisms suggested the need for caution and the resilience of the client to be considered. Participants all reported that the task triggered curiosity and perspective taking, both features of mentalizing, although the genogram was not introduced with this as an objective. Combining art and genograms as a therapeutic intervention offered the therapist a tool that could possibly assist in the development of a mentalizing stance for both themselves and the client. While these findings were not conclusive they do indicate potential benefits for the therapist working from a mentalization stance.