Approximately 37 per cent of architectural students are women and the percentage is increasing. This increase is not reflected in the architectural profession; women represent only 13 per cent of the total and analysis reveals that women are leaving the profession after qualifying. The research reported here was undertaken in 2003 and investigated the reasons why women were leaving. Research methods included the appointment of an expert advisory group, an extensive literature review, a web-based questionnaire aimed at women architects and a series of interviews with women who had left architecture. No single reason emerged from the research to explain why women left but a multiplicity of factors, such as low pay, poor promotion prospects, discriminatory attitudes and sexist behaviour were found to influence departure. The problem has an international dimension as revealed through the web survey and from ongoing academic interest. There are serious implications for the future of the profession if, through its culture and practice, it loses skilled people after they have qualified. Finally a series of key strategic recommendations for the professional bodies as well as practitioners suggest ways of reducing this female brain drain. The aim is to increase diversity in the construction industry and improve the competitive edge of the architectural profession.