Objective: To describe group B streptococcal (GBS) disease prevention practices of obstetrician-gynecologists. Methods: We surveyed 1019 ACOG Fellows—the 419 members of the Collaborative Ambulatory Research Network (CARN) and 600 randomly selected non-CARN Fellows. Results: There were 601 eligible respondents. More than 95% in both the CARN and the non-CARN groups reported adopting one of three GBS prevention strategies. The most commonly reported strategy was a combination approach not described in the consensus guidelines. The second most common strategy was the screening-based strategy; the risk-based strategy was third. Most respondents provided GBS information to all prenatal patients, but those using a risk-based strategy and those in solo practice were less likely to do so. Less than 60% in each group used penicillin as their first choice for GBS prophylaxis. More than 20% in each group who routinely screened for GBS did not collect both vaginal and rectal cultures. Respondents rated ACOG publications as the most important influence on their GBS prevention approach. Conclusion: Almost all ACOG Fellows have adopted a GBS prevention strategy. The importance of providing GBS prevention information to all patients, use of penicillin, and collection of both vaginal and rectal cultures should be reinforced.