This paper summarizes the nursing experience of PICC successfully retained in the affected arm in a patient undergoing left-sided modified radical mastectomy for left breast cancer and right breast reconstruction.Nursing priorities included preoperative multidisciplinary assessment of the pros and cons of retaining the PICC line, formulating and implementing a comprehensive care plan, strengthening symptom management, providing rehabilitation exercises, nutritional support, psychological rehabilitation, and continuous care.The patient was hospitalized for 18 days postoperatively, with good wound healing, and discharged with the PICC line.After discharge, relevant treatments continued and PICC line was removed when all treatments were completed.The total indwelling time was 338 days (128 days before admission, 85 days during hospitalization, and 125 days after discharge), and no PICC-related complications occurred.