In 1985, the American Osteopathic Association (AOA) changed its educational policies to permit osteopathic postdoctoral programs in settings that were accredited by the Accreditation Council for Graduate Medical Education (ACGME). In response to this policy change, an existing ACGME-accredited emergency medicine residency was modified to create a combined osteopathic/allopathic residency program that meets the educational requirements of both the AOA and the ACGME. Our 10-year experience with this combined osteopathic/allopathic emergency medicine residency is described in terms of program development, governance structure involving key stakeholders, faculty distribution--equal numbers of allopathic and osteopathic faculty, and educational outcome of the total number of residents graduated (93 graduates, with 33 osteopathic physicians and 60 allopathic physicians). Lessons learned from the 10 years' experience of this combined residency program, as well as current issues, are explained. The future potential of such dual-approved programs on the supply of residency positions is discussed from the viewpoint of osteopathic postdoctoral education.