Pediatric oncology has become a highly specialized area, and the transition from novice nurse to expert can be complicated. The aim of this study was to describe the perceptions of nurses in pediatric oncology regarding the role of an expert nurse in pediatric oncology. Nurses (n = 66) working in pediatric oncology participated by writing their narratives. The data were analyzed by means of content analysis, and 3 categories were found: an expert has confidence in his or her knowledge, an expert provides high-quality care, and an expert is given possibilities for professional growth. It can be concluded that when nurses are given possibilities for continuous education and reflection, and have a feeling of satisfaction at being able to fulfill a child and his or her family's needs, this enhances their possibility to become experts and maintain expert competence.