Objective: Nursing care plans for oncology patients are complex and overlapping enough to warrant the need for systematised documentation that ensures high quality, flawless and comprehensive care. Addressing the patients’ needs through nursing diagnoses is the initial step that shapes the subsequent care. Therefore, the current study aimed to identify the frequent NANDA-I diagnoses reported in nursing care plans for medical oncology patients.

Data sources: A retrospective design was used to collect data from 260 electronic nursing care records of oncology patients admitted to medical floors at an accredited oncology centre in Jordan.

Conclusion: The complexity of nursing care for oncology patients can be inferred from the high number of reported nursing diagnoses. This study summarises the most common nursing diagnoses and their combinations that can be used as a guide to formulate nursing care plans for oncology patients in medical units.

Implications for nursing practice: Oncology nurses may refer to this study to guide and support their care and documentations to maintain a high standard of nursing practice. Besides, the reported diagnoses can be integrated to generate pre-printed, standardised nursing care plans, where diagnoses are listed for nurses to select the applicable ones for their patients. Similarly, the combinations of nursing diagnoses may guide nurses to search for a concurrent diagnosis, thus improving patients’ outcomes. This study revealed the complexity of patients’ care in medical oncology units, which alarms the nursing managers to reconsider the nurse–patient ratio in these settings to meet patients’ care demands and maintain their safety.