When this journal was first published 20 years ago, discussions about systems of continuing education were just beginning. Houle had just published his landmark book Continuing Learning in the Professions, in which he predicted that continuing education would grow in stature and size to rival pre-service professional education. The purpose of this article is to critically analyse the developments in CPE over this 20-year period. Although we have witnessed the partial realization of Houle's prediction, we are in a transitional period of building systems of continuing education. I review five trends that have greatly affected the face of CPE over the past twenty years. These are: (1) the amount of continuing education offered at the workplace dwarfs that offered by any other type of provider, and probably all other providers combined; (2) an increasing number of programmes are being offered in distance education formats by universities, professional associations and for-profit providers; (3) there are increasing collaborative arrangements among providers, especially between universities and workplace; (4) the corporatization of continuing education has increased dramatically; and (5) continuing education is being used more frequently to regulate professional practice. I end by discussing three issues currently being negotiated across the professions related to the future development of systems of continuing education. These are: (1) continuing education for what? - the struggle between updating professionals' knowledge and improving professional practice; (2) who benefits from continuing education? - the struggle between the learning agenda and the political and economic agendas of continuing education; and (3) who will provide continuing education? - the struggle for turf versus collaborative relationships.