Pregnant women and infants aged <6 months are at increased risk for influenza-related severe illness and hospitalization. Influenza vaccination of pregnant women has been shown to reduce the risk for illness in both mother and infant. To help protect pregnant women, the Advisory Committee on Immunization Practices (ACIP) and the American College of Obstetricians and Gynecologists recommend influenza vaccination for all women who are or will be pregnant during the influenza season, regardless of trimester. To estimate influenza vaccination coverage among pregnant women during the 2012-13 influenza season, CDC analyzed data from an Internet panel survey conducted April 1-12, 2013. Among 1,702 self-selected survey respondents pregnant at any time during the 4-month period of October 2012-January 2013, 50.5% reported they received influenza vaccination before or during their pregnancy. Influenza vaccination coverage was higher among women reporting both a health-care provider recommendation and offer of influenza vaccination (70.5%) compared with women who received a recommendation but no offer of vaccination (46.3%) and women who received no recommendation (16.1%). Vaccination coverage of women who will be or are pregnant during an influenza season might be improved by implementing a combination of community-based interventions, including enhanced access to low-cost vaccination services, provider recommendation and offer of influenza vaccination, and education of pregnant women about influenza vaccination safety and efficacy during pregnancy to increase demand.