Children's right to participate in their own healthcare has increasingly become highlighted in national and international research as well as in government regulations. Nevertheless, children's participation in healthcare is unsatisfactorily applied in praxis. There is a growing body of research regarding children's participation, but research from the children's own perspective is scarce. The aim of this study was thus to explore the experiences and preferences for participation in healthcare situations among children with juvenile idiopathic arthritis (JIA) as a foundation for creating strategies to promote their participation in pediatric healthcare. Twenty children, aged 8 to 17 years, with JIA were interviewed individually and in focus groups. In order to increase the children's opportunities to express their own experiences, different interview techniques were used, such as draw-and-tell and role play with dolls. The analysis was conducted with a constructivist grounded theory. The result explores children's perspective of influencing processes promoting their participation in healthcare situations. The core category that emerged was, "Releasing fear and uncertainty opens up for confidence and participation," and the categories related to the core category are, "surrounded by a sense of security and comfort," and "strengthened and supported to become involved." In conclusion, the knowledge gained in this study offers new insights from the perspective of children themselves, and can constitute a valuable contribution to the understanding of necessary conditions for the development of specific interventions that promote participation among children in healthcare situations.