Nurses who take care of patients with hematology have more difficulty in therapeutic communication. The aim of this study is to explore the therapeutic communication experiences of nurses caring for patients with hematology and the meaning of the essential structure of therapeutic communication. Colaizzi’s phenomenological method was applied to explore the essential structures and meanings of therapeutic communication in depth through a focus group interview. The interview was conducted at a tertiary care hospital with 20 nurses caring for patients with hematology. As a result of the analyses, 22 themes, 14 theme clusters, and 5 categories were derived. The categories derived from the analyses included “acquiring core competencies as nursing professionals”, “improving patient-centered nursing performance”, “forming a partnership treatment relationship”, “obtaining clinical performance skills to solve problems”, and “preparing efficient system improvement”. Based on this study’s results, it will be possible to provide high-quality nursing to patients by improving the therapeutic communication ability of nurses caring for patients with hematology. In addition, it will be the basis for the development of a nurses’ therapeutic communication promotion program for nurses caring for such patients.