BACKGROUND: The issuance in 2002 of new guidelines recommending universal screening for group B Streptococcus (GBS), a leading cause of neonatal sepsis in the United States, has created a new opportunity to educate women of childbearing age to be active partners in prevention. METHODS: To assess baseline levels of awareness about perinatal GBS, we analyzed responses to a question included in a health communications/social marketing survey in 1999 and 2002. RESULTS: Among the 2917 women under 50 who responded, 47% reported ever having heard of perinatal GBS. Among women pregnant at the time of the survey, awareness was 66%. Women with a high school education or less (OR = 0.60, 95% CI 0.50-0.73), household income <25,000 US dollars (OR 0.65, 95% CI 0.54-0.79), or reporting black, Asian/Pacific Islander, or other race (ORs [95% CI] 0.70 [0.57-0.87], 0.61 [0.41-0.90], 0.41 [0.20-0.85], respectively) had lower awareness of perinatal GBS than other women. Women currently pregnant (OR 2.2, 95% CI 1.5-3.3) had higher awareness. CONCLUSIONS: Awareness of perinatal GBS is high among currently pregnant women, for whom this issue is most important. Efforts to raise awareness should be targeted to women from traditionally underserved populations, such as those who are of nonwhite race or who have lower educational attainment or household income.