The Tree Theme Method (TTM) is an intervention based on sessions involving creative activities and life storytelling/story-making, in which the client paints trees representing various periods of his/her life. The aim of this study was to investigate clients' experiences of participating in a TTM intervention and their perceptions of the therapeutic relationship. Thematic interviews were undertaken. Twenty clients attending general outpatient mental healthcare units were recruited after having participated in the intervention. A qualitative content analysis resulted in six categories: “From feeling a pressure to perform to becoming focused and expressive”, “Expressing oneself and one's life situation led to awakening of memories and feelings”, “New perspectives of self-image, everyday life and relations to others”, “Story-making led to shaping and reconstructing one's life story”, “Interaction was of importance when reconstructing one's life story” and, finally, “The attitude of the occupational therapist was of importance for the development of the therapeutic relationship”. There seemed to be a close association between the intervention and the therapeutic relationship in starting a process of opening up new perspectives on everyday life, but there is a need for further studies including therapists' experience of using the TTM and their perception of the client–therapist relationship.