Objectives: This study aimed to provide foundational data to establish a cooperative management system for dental hygienists. This was achieved by exploring the meaning of oral health care as experienced by nursing care workers when caring for older adulys and by gaining an understanding of its essential structure. Methods: A qualitative phenomenological research design was employed. Data were collected through individual in-depth interviews conducted with 12 nursing care workers between September 1 and October 10, 2025. The participants were selected based on their experience in providing daily care for older adults. All interviews were audio-recorded, transcribed verbatim, and analyzed using Colaizzi’s phenomenological method, which involves identifying significant statements, formulating meanings, organizing subcategories, and deriving essential themes. Results: A total of 140 meaningful statements related to oral health care experiences were extracted from the interview data. These statements were organized into 12 subcategories, which were further integrated into five thematic clusters and refined into five central meanings. The identified central meanings included path chosen at a turning point in life, daily care involving rewards and responsibilities, beginning of oral health, continuing oral care practice, and sharing dreams with experts. These f indings illustrate how nursing care workers perceive oral health-care to be closely connected to both physical health and the quality of everyday care for older adults. Conclusions: Nursing care workers viewed oral health care not merely as a daily task, but as an integral aspect of life changes, daily care, limitations of their abilities and their aspiration to collaborate with experts. This information can inform future discussions on cooperative oral health-care systems involving nursing care workers and dental hygienists.