Survival rates and side effects have become the dominant constructs of cancer treatment and care, to the detriment of more supportive and patient-focused approaches. The concept of quality of life introduced to address this has failed to temper the language of oncology. Here an argument is made for the place of cancer nursing as a therapeutic enterprise in its own right, which warrants much greater recognition. Clear evidence for the therapeutic effects of cancer nursing intervention from a series of meta-analyses of cancer nursing interventions exists. Cancer nursing as therapy has the potential to operate on four levels and can effect radical change by reconstructing care, cancer services, and wider health care environments so that they are much more patient focused and offer nursing therapy as an integral part of care. These include fundamental knowledge or theory generation for therapeutic practice, therapeutic interventions for individuals or problems, developing and changing health systems or environments, or critique and reconstruction of care from a societal perspective. The features of cancer nursing as therapy can be identified and are described. Cancer nurses are encouraged to take up the challenge offered by the concept of therapeutic cancer nursing so that its potential for nurses, patients, and cancer services can be realised.