Objective: The objective of the study was to determine the prevalence of bacterial vaginosis and the distribution of associated morphotypes among asymptomatic pregnant women in different countries. Study design: In 8 institutions participating in the Global Network for Perinatal and Reproductive Health (www.gnprh.org) from July 1999 to September 2001, 1466 women were enrolled. Vaginal smears were Gram stained and scored with Nugent's method at a reference laboratory. The prevalence of bacterial vaginosis and bacterial morphotype distributions were compared. Results: Overall, 12.3% of women had bacterial vaginosis according to Nugent's criteria. Zimbabwe had the highest prevalence (24.4%) when compared with all other sites, except Myanmar (P < .05). Among bacterial vaginosis cases, 98.9% of vaginal smears had more than 30 Gardnerella/Bacteroides morphotypes present per oil immersion field. Individual centers showed significant differences in the number of Mobiluncus and lactobacillus morphotypes (P < .01). Conclusion: The prevalence of bacterial vaginosis and distribution of bacterial morphotypes in vaginal smears among asymptomatic pregnant women vary significantly in populations from different countries. © 2006 Mosby, Inc. All rights reserved.