The objective of this study was to identify factors related to failure to receive recommended interventions for the prevention of mother-to-child HIV transmission among HIV-infected pregnant women in the United States. Using Enhanced Perinatal Surveillance data from 2005 through 2008, we identified characteristics of HIV-infected women (n = 5,391) that increased their odds of missing an opportunity to prevent perinatal HIV transmission. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were calculated by using backward step-wise logistic regression analyses to determine the relationship between demographic variables and missed opportunities. Of 4,220 HIV-infected pregnant women with complete data, 2,545 (60%) did not receive all of the recommended interventions. Missed opportunities for prevention occurred more often among HIV-infected women aged 25-34 years (aOR = 1.9, 95% CI = 1.4-2.5), and greater than 34 years (aOR = 2.0, 95% CI = 1.5-2.7) compared to those 13-19 years and among injection drug users (aOR = 1.3, CI = 1.0-1.5) compared to women infected with HIV through heterosexual contact. Clinicians can decrease missed opportunities by routinely providing recommended interventions, especially among HIV-infected women who are injection drug users or aged 25 years or older.