In the light of increasing emphasis upon mandatory continuing education in nursing, the need for cancer nurses to update and improve their knowledge and skills is heightened. The challenges lie in how to keep nurses up-to-date, broaden their outlook and ensure that patients benefit. In this paper the literature on the purpose and benefits of continuing education is reviewed, and the implications of the Post-Registration Education and Practice Project (PREPP) for cancer nurses are addressed. Arguments about a definition of 'continuing learning' rather than 'continuing education' are discussed, since outcomes vary depending upon the definition adopted. Inconsistencies between the benefits claimed and those measured are highlighted. Attention is drawn to the inconclusive nature of the studies that have measured impact; some of the problems encountered in the provision of adequate education and its accessibility to nurses; and the continuing discrepancy of perceived need between nurse and manager. Specific impact evaluation studies relating to continuing education in cancer nursing are reviewed. Recommendations for providing education with measurable outcomes are drawn from the literature, while a case is made for the alternative perspective of lifelong learning where outcomes are neither specific nor measurable. In conclusion, the questions of who should be responsible for education and the need for further development of impact evaluation tools are addressed.