Admission to hospital is recognised as a difficult time for children and families. This study explored clown doctor activities in an acute paediatric setting and the impact their activities have on children, their families, other health professionals and clown doctors themselves. We used observation, semi-structured interviews and focus groups with children and parents and staff and clown doctors and results provide a rich description of the work of clown doctors. The major themes were 'the encounter - in the moment' of the interaction of the child and the clown doctor and 'beyond the encounter'. The findings show that the impact of clown doctor visits is experienced beyond the immediate interaction, and this has not been clearly articulated in previous studies. This study highlights the multifaceted and complex nature of the work of the clown doctors and the high level of skill required as they modify and interpret play, activities and environment based on individual need and response.