RESUMEN
It is hereby presented a quality control study of a systematic vaccination program developed in an urban primary care center. Target population were children between 0 and 8 years attended in the center. They were considered as having a correct vaccination coverage those cases in which it was possible to verify documented accomplishment of the local vaccination schedule. Out of the 538 children included in our study, 168 (31%) were founded not to have appropriate vaccination coverage evidenced in their clinical records, and their families were requested for an interview: 126 (75%) attended de appointment. In 93 of them it was founded a recording mistake, and 33 cases were verified as no correctly covered. Vaccination coverage rate was 86%, being inverse relationship between age and coverage rate. They are discussed corrective actions derived from the quality control.