Nurses are responsible for the well-being and quality of life of many people, and therefore must meet high standards of technical and ethical competence. The most common form of ethical guidance is a code of ethics/professional practice; however, little research on how codes are viewed or used in practice has been undertaken. This study, carried out in six European countries, explored nurses' opinions of the content and function of codes and their use in nursing practice. A total of 49 focus groups involving 311 nurses were held. Purposive sampling ensured a mix of participants from a range of specialisms. Qualitative analysis enabled emerging themes to be identified on both national and comparative bases. Most participants had a poor understanding of their codes. They were unfamiliar with the content and believed they have little practical value because of extensive barriers to their effective use. In many countries nursing codes appear to be 'paper tigers' with little or no impact; changes are needed in the way they are developed and written, introduced in nurse education, and reinforced/implemented in clinical practice.