Mental health nurses are relative latecomers to nurse prescribing. This is primarily because nurse prescribing has been seen as more appropriate for general nurses, particularly those working in the community or primary care. Pharmacists and psychiatrists were concerned about the complexity of prescribing for clients with mental health problems and felt that the training of mental health nurses and their clinical experience did not fit them to take on a prescribing role. These, and other impressions, may have influenced which groups of nurses were first selected to become nurse prescribers. However, recent studies have indicated that mental health nurses add considerably to the effectiveness of assessments and care plans, and that they are in an ideal position to integrate drug treatments with a wide range of non-pharmacological therapies knowledgeably, safely, effectively and in a manner that is acceptable to the patient. They have also been found to have an important role to play in monitoring the side effects of drugs and in providing education about medication, and in maintaining a therapeutic alliance with clients on long-term drug treatment. Whatever the limitations, mental health nurses as prescribers may still be deemed to have by some professional groups, and even by themselves, at this stage in the evolution of nurse prescribing, it is now inevitable that they will play a significant part in the overall improvement of mental health services during this decade. They are likely to challenge the existing prescribing practices and help in identifying the conditions under which medication is most therapeutic.