OBJECTIVES: To critically assess the prevalence among schoolchildren 6 to 9 years of age throughout the Dominican Republic of a bacille Calmette-Guérin (BCG) vaccination scar, and to examine the relationship between nutritional and sociodemographic factors and the likelihood of having a BCG scar. METHODS: This correlational study used the database of the Second National Census on Height and Weight of Elementary School First Grade Students, which was conducted in the Dominican Republic August 2001-May 2002, to provide a critical assessment of BCG coverage nationwide. The Census information for the children included the presence of BCG scar, their nutritional status, and basic demographic data. We developed a new sociodemographic indicator, the "Rosa Index," to examine the potential influence of poverty and other environmental characteristics on scar presence. We used logistic regression models to predict the presence of a BCG scar. RESULTS: An overall BCG scar prevalence of 55.3% (85 644/154 887) was found. Malnourished children were less likely to have a BCG scar than were children with adequate nutritional status (odds ratio = 0.91; 95% confidence interval: 0.87, 0.95, P < 0.05). Children who were 7-9 years old were less likely to have a BCG scar than were children 6 years old. Children in the areas of the country more than two hours' driving distance from the capital city of Santo Domingo more often exhibited lower BCG scar prevalence levels than did children in Santo Domingo. A higher Rosa Index (better level of socioeconomic characteristics) was correlated with higher BCG scar prevalence values (r = 0.54, P < 0.05). CONCLUSIONS: Our study findings indicate that BCG coverage appears to be inadequate for schoolchildren in the Dominican Republic. Nevertheless, the presence of a scar in a higher proportion of younger children suggests that coverage has improved in recent years. More programmatic and economic emphasis needs to be placed on extending early BCG vaccination coverage to the areas of the country where vaccination coverage is lower, and on examining the potential role that poverty may have on vaccination effectiveness.