Extending nurses' roles and responsibilities so that they may take on some functions of doctors is widely advocated to assist with shortages of medical staff, improve service provision, and to reduce costs. In cancer care in particular, use of specialist nurses to help meet targets for faster diagnosis and treatment is seen as essential. However, there has been little detailed investigation of the consequences, effectiveness, or acceptability of doctor-nurse substitution across health care, or more specifically in cancer services. In this article, I review the evidence for nurse-led care in cancer.