This thesis examined children's experiences of therapy and used grounded theory (Strauss & Corbin, 1998) to develop a theory that may explain this. Eighteen children aged 7-14 years who had attended therapy at a child and adolescent mental health service or school-based therapy service participated in an individual interview. The study found that therapy is a process for children and identified sub-processes and activities that work to affect children's experiences of therapy. The professional practice component is a case study describing the use of cognitive behaviour therapy with a thirteen-year-old girl presenting with symptoms of anxiety. The literature review component is a critical review of the empirical literature on the use of motivational interviewing with children.