Therapeutic computer games might enhance children's motivation for psychotherapy, facilitate their understanding of important therapeutic concepts, structure therapy sessions, enhance treatment of migrant children and disseminate evidence-based treatment approaches. The game Treasure Hunt was developed to support cognitive behaviour therapy with children who come into treatment for various mental health problems. To evaluate the applicability and appropriateness of the game, 124 therapists answered a questionnaire on their impression of Treasure Hunt three months after download. Of these, 42 consented to participate in the further evaluation and sent questionnaires of 218 children in whose therapy Treasure Hunt had been used. A limitation of these data is an eventual positive bias, as therapists with a positive attitude towards therapeutic computer games may have been more likely to participate. Data show that the vast majority of children were satisfied their therapist had used the game during treatment. Therapists used Treasure Hunt for a broad range of diagnoses. They judged the game as helpful in the explanation of cognitive-behavioural concepts, used it as reinforcement and reported it enhanced child motivation for psychotherapy and strengthened the therapeutic relationship with the child.