Clinical nurse specialism is an important and integral part of nursing in the 21st century but when did it start? Since the time of Florence Nightingale, nursing has grown and developed as a profession. Part of this growth, particularly in relation to professional development, has resulted in nurses focusing on, or specialising in, particular areas of nursing care and the development of clinical nurse specialism and advanced practice. The USA led the way in this field, followed closely by the UK and the rest of Europe, Australia and Asia. This has led to a proliferation of nurses working in specialised areas and advancing nursing practice.