There has been substantial growth in the provision of midwifery-led models of care, yet little is known about the obstetric consultation and referral practices of these midwives or the quality of the collaboration between midwives and obstetricians. This study aimed to describe these processes as they are practised in New Zealand, where midwifery-led maternity care is the dominant model. A total population postal survey was conducted that included 649 New Zealand midwives who provided midwifery-led care in 2001. There was a 56.5% response rate, describing care for 4251 women. Within this cohort, there was a 35% consultation rate and 43% of these women had their lead carer role transferred to an obstetrician. However, the midwives continued to provide care in collaboration with obstetricians for 74% of transferred women. Seventy-two percent of midwives felt that they were well supported by the obstetricians to continue care. Midwifery-led care is reasonable for the general population of childbearing women, and a 35% consultation rate can be seen as a benchmark for this population. Midwives can, when well supported, provide continuity of care for women who experience complexity during pregnancy and/or birth. Collaboration with obstetricians is possible, but there needs to be further work to describe what successful collaboration is and how it might be fostered.