Vaccines are important tools for disease prevention and, in obstetric patients, to prevent transmission to infants. Obstetrician-gynecologists are well situated to screen for immunization status of women of child-bearing age and to provide appropriate vaccinations. A series of research investigated obstetrician-gynecologists' beliefs, practices, and knowledge regarding immunization. Surveys were sent out in 2007 to Fellows of the American College of Obstetricians and Gynecologists. Most obstetrician-gynecologists viewed screening for vaccine-preventable diseases to be within their professional role, and a majority administers at least some vaccines. Over half agreed financial factors (eg, inadequate reimbursement, cost of storing vaccines) were barriers to vaccine administration. Other perceived barriers were a concern over safety of vaccinations during pregnancy and a view that administering vaccines was not part of their usual practice. They were also concerned about their level of training. A majority believed their immunization training was less than adequate, and believed their practice would benefit from continuing medical education courses. One study identified changes in Michigan obstetrician-gynecologists' attitudes, knowledge and practices since 2000. More Michigan ob-gyns are assessing vaccination needs, viewing this as part of their professional purview, and, in general, their knowledge of vaccine recommendations has improved. Concerns over the safety of vaccines in pregnancy as well as financial burdens of immunization have increased. Immunization is an important part of women's health care and has been, at least partially, incorporated into obstetrician-gynecologist practice. Financial burdens and physician concerns over training remain barriers to vaccine administration.