Introduction The breastfeeding is extremely important to the general's and stomatognathic system's health of the baby. The aim of this research is to evaluate the existing association between breastfeeding and deleterious oral habits and the prevalence of the habits in children from 03 to 05 years old in Vitória, Espírito Santo.

Methods Case-control study, used as parameters to the samples a prevalence of 33%, confidence level of 95% and margin of error of 5%. The final sample was 903 students, randomised and representative of a total of 9829 children, with complete primary dentition. For the data collection it was used a questionnaire directed to the responsibles. The comparison of the percentages among habits and socioeconomic factors and weaning was tested by Fisher's exact test. To the risk it was used OR. The level of significance was 5%. The statistic package SPSS-Social Package Statistical Science, version 15—was used to this analysis. This research was approved by Comitê de Ética em Pesquisa da UFES (084/2010).

Results 12.4% present or had presented the habit of finger sucking and 37.7% the habit of sucking pacifier. There is no statistically significant association of the habit of finger sucking with weaning and children who suffer weaning present approximately 4 times more chance of developing the habit of sucking pacifiers.

Conclusion It is necessary a larger awareness of the mothers about breastfeeding and public politics to create conditions for them to have these healthy choices.