Vaccination coverage in a representative sample of children under 3 years of age in Catalonia (Spain) was studied. Parents of children selected were contacted and asked for the child's vaccination card. A total of 630 children were included, of whom 570 were indigenous and 60 immigrants. Primary vaccination coverage was 96.5% for indigenous and 85% for immigrant children (p=0.0001), while the coverage of primary vaccination plus booster doses was 88.6% in indigenous and 78.3% in immigrant children (p=0.02). Efforts should be made to increase primary vaccination coverage in immigrant children and booster dose coverage in both indigenous and immigrant children.