AIMS: The intense emotional nature of cancer care makes it crucial for oncology nurses to effectively regulate their emotions, as this impacts their mental health, quality of care, empathy challenges, burnout, and workforce retention. The aim of this study is to determine oncology nurses' experiences with emotion regulation during patient care and how these experiences affect their well-being and the quality of patient care. METHODS: This descriptive qualitative study used a sample of 28 oncology nurses from various units, collected data through in-depth semistructured interviews, and analyzed it using content analysis. RESULTS: Emotion regulation challenges encompass situations related to perspective and skills, patient-related conditions, and work-related issues. Emotional responses differ between the first and later years in the profession. Methods used include avoidance, alleviating the emotional burden, and cognitive restructuring, while needs involve gaining awareness and skills to regulate emotions and improving working conditions. CONCLUSIONS: This study provides insight into how oncology nurses regulate their emotions during patient care and discusses the positive and negative effects of the emotion regulation strategies used on their mental health. Nursing professionals who struggle with emotion regulation during their early years in the profession describe experiencing burnout and compassion fatigue in the later stages of their careers. Beginning nurses are inexperienced with challenging emotions. They should be trained to regulate their emotions. IMPLICATIONS FOR PRACTICE: Oncology nurses struggle with regulating their emotions during patient care, which leads to mental health issues and burnout over time. Therefore, it is important to develop effective emotion regulation skills. The research findings can contribute to planning emotion regulation training for oncology nurses and help managers pay attention to working conditions.