INTRODUCTION. In Colombia and worldwide the vaccination is a strategy that has reduced infant mortality, but there were low coverage in some areas of the country, in the causes of the non-vaccination is the low birthweight, very important issue and little studied, meeting as a controllable cause and which allow the population access to protection against immunopreventable diseases. MATERIALS AND METODS. Observational study of crosscut was conducted; the sample was taken from the ENDS by Profamilia in 2010, the total number of respondents who met the inclusion criteria, in total there were 9694 records that then underwent descriptive, bivariate and multivariate analysis. RESULTS. Children with low birthweight are less likely to be vaccinated with the complete scheme with regard to children with normal weight, OR 0762 (95% CI 0. 650, 0. 895), was observed that vaccines individually have a behavior similar to complete scheme, specifically on application in time for your application, except triple viral where no association was found. CONCLUSION. The low weight is a determinant factor in timely vaccination of children and the subsequent performance of the scheme, variables associated was found with the non-compliance as the place of birth, the poverty rate and ethnicity belong to African descent were found.
