Early childhood education and care (ECEC) workers and hospital play specialists (HPSs) share a role in supporting the development of sick children through play while respecting their autonomy. On the other hand, in supporting children’s play, managing their anxiety, and making environmental arrangements for them, ECEC workers and HPSs play different roles. When supporting the development of sick children, the former should respect their autonomy and make the most of the characteristics of ECEC as a measure to comprehensively support their participation in play, including it in their daily lives. ECEC workers are also expected to contribute to the further development of comprehensive support by promoting collaboration and cooperation with various professionals, including HPSs.