Background This article explores how children use fantasy, play, and coping (imaginal coping) in order to handle chronic illness. Imaginal coping, as a theoretical construct, is defined as the use of imagination to deal with the hardships of illness. The overarching aim has been to investigate the various ways in which categories of staff members (doctors, nurses, play therapists, and hospital clowns) and parents support children in their coping. Focus has thus been on collaborative or interactive aspects of playful coping. Method A large proportion of the data collected consists of 93 h of video‐recorded interactions between children, parents and staff. The collection of data involved fieldwork carried out with the use of a video ethnographic method, making it possible thereby to analyse and work with data in greater detail. For more than one year, five children with leukaemia were followed as each made their regular visits to a children's cancer clinic in a children's hospital in Sweden. Results Collaborative storytelling, humorous treatment practices, playful rituals, as well as role‐reversal play, were all types of events involving staff–child collaboration and creative improvisation. Conclusions Staff, along with parents, played a significant role in the coping process. In various ways, the staff members helped the parents to respond to their children in ways adaptive for coping. It can be seen that imaginal coping is a highly interactional business. In this study it is shown that parents socialize coping; this is sometimes undertaken explicitly, for example, through coaching (in the form of instructions or suggestions) and teaching. But often it is achieved through modelling or intent participation, with the child observing staff members' treatment practices.