The aim of this mixed-method study was to explore the effects of hippotherapy on people with cerebral palsy, and to investigate how these effects are being evaluated. Germany and the UK were chosen as study locations for their differences in history and availability of hippotherapy. A questionnaire survey of physiotherapists practising hippotherapy sought to establish clinicians' perceptions of the effects of hippotherapy on this user group and to investigate current practices in the evaluation of outcome. It also served to contextualise the study in terms of practice and resources. This was followed up with focus groups to investigate with physiotherapists how hippotherapy outcomes can be evaluated. Focus groups and individual interviews were used to explore the effects of hippotherapy from the perspective of users and parents. The results are remarkable in several ways. Not only was this the first study to investigate hippotherapy from a user perspective, users and parents discussed a range of issues that went well beyond answering the key questions. Thus, users provided unique and new insights into the effects of hippotherapy, the context in which hippotherapy happens, as well as its effects and the impact of these effects on them in terms of activity, participation and quality of life. Two of the key findings of this study were that hippotherapy is experienced as being more effective than conventional physiotherapy and a difference in effectiveness of hippotherapy in the UK and in Germany. The comprehensive information users shared was triangulated with physiotherapists' observations expressed in the questionnaire survey and existing literature to establish theory to account for these findings. This resulted in the development of a conceptual framework to explain why hippotherapy provides such an effective opportunity for motor learning, something that had not been attempted before. This was the first study to comprehensively explore the effects of hippotherapy on people with cerebral palsy. Its findings can serve as the basis for further study in this specialist area within physiotherapy