This paper reports on one aspect of the evaluation of the midwifery pilot projects in Quebec: the identification of the professional and organizational factors, as well as the mode of integrating midwives into the maternity care system, that would promote the best outcomes and the autonomy of midwives. The research strategy involved a multiple-case study, in which each midwifery pilot project represented a case. Based on a qualitative approach, the study employed various sources of data: individual interviews and focus groups with key informants, site observations and analyses of written documents. Results show that midwives were poorly integrated into the health care system during the evaluation. Four main reasons were identified: lack of knowledge about the practice of midwifery on the part of other health care providers; deficiencies in the legal and organizational structure of the pilot projects; competition over professional territories; and gaps between the midwives' and other providers' professional cultures. Recommendations are provided to facilitate the integration of midwives into the health care system.