Child life services is a professional service that supports children and adolescents seeking medical treatment. These services provide age-appropriate medical understandings and psychological preparation, coping skills, and psychosocial support for children with the goal of reducing fear, anxiety, and psychological trauma during healthcare provision. In addition to supporting young patients, child life services also support family members and caregivers, facilitating their effective response to related disease and medical situations. Child life specialists are experts in providing child life services. This article reviews the historical development of child life services, including its development and theory, related professional training and education, and the application and intervention goals of child life services in medical care. Finally, the establishment and developmental model of promoting child life services in Taiwan are reviewed with the goal of providing information for the promotion and utilization of child life services by healthcare professionals in practice settings.