Hospitalization in childhood can be characterized as a stressful and distressing event for patients and families, especially in cases of illnesses or chronic conditions that require pediatric palliative care (PPC). The hospital psychologist who works in PPC contributes, among other things, to minimize the suffering resulting from illnesses. The purpose of this article was to report the experience of participant observation, as a field activity of a Psychology guided research practice discipline, about the work in PPC of a psychologist in a public hospital in the South of Brazil. This is an observational study, of a qualitative and descriptive nature, of six episodes of participant observation recorded by a Psychology undergraduate in a field diary and analyzed through categorical content analysis. During the observations, the psychologist worked with nine companions and eleven children in hospitalized PPC. It was found that the most required activities for the psychologist were the following categories: listening and supporting family members, to express emotions and encourage self-care; mediation between family members and the healthcare team, for better communication; playful activities with children, to distract and form bonds; and doing records in medical records, to inform and guide the team. In the field of PPC, the psychologist's work must be based on a biopsychosocial perspective of individuals, with the purpose of promoting comprehensive and humanized care. However, considering the complexities present in PPC and the tensions inherent to the hospital context, the psychologist must also be aware of his self-care needs during his professional practice.