WHO-Europe's goal is to eliminate measles and rubella by 2010 which will require a coverage rate of 95% for both MMR-vaccine doses. Belgian recommendations include a first MMR vaccine at 12 months and a second at 10-12 years of age. To survey MMR vaccination coverage, EPI two-stage random cluster samples of 1,500 toddlers (18-24 months of age), 900 primary school children (born in 1997), and 1,500 adolescents (born in 1991) living in Flanders (Belgium) were drawn. Documented MMR-vaccination was recorded and a questionnaire on sociodemographic factors was completed at home by trained interviewers in 2005. Missing data were retrieved from well-baby clinics and school health service documents. The overall response rate was 89.5%, leaving 3,490 subjects fit for analysis. MMR coverage (first dose) was 94.0% in the toddler group, 88.0% in the 7-year-olds, and 80.6% in adolescents. The 10- to 12-year dose was documented in 83.6% of the adolescents, but only 74.6% had proof of both MMR vaccines. A lower MMR coverage was noted in single or divorced parents (toddlers, adolescents), families with more than four children (toddlers, adolescents), non-Belgian parental origin (children, adolescents), lower education or unemployment of parents (toddlers, children, adolescents), low family income (children, adolescents), vaccination by the GP (toddlers, children), and education-related factors (children, adolescents). The recommended WHO coverage rate of 95% for MMR is within reach in toddlers. Documentation of vaccination is a major concern in older age groups and may explain lower coverage estimates. Children growing up in a less privileged environment deserve special attention.