This paper is a qualitative family therapy process study which is part of a larger European-based outcome study comparing family therapy to child psychotherapy plus parent support for depressed children and their families. The family therapists and two clinical supervisors from the original study formed themselves into a research team to study the process of therapy with twelve families. Therapists selected the significant moments from fifty-nine sessions, and were then interviewed by the research team using a standard protocol to investigate the therapists' own thinking about the significant moments. Applying a thematic analysis, the significant moments were clustered into eleven themes. The paper discusses the rationale for this model of research, which is well suited for clinical teams, and the application of the themes to therapeutic work with depressed children and their families.