Aim The objective of this systematic review was to investigate whether breastfeeding decreases the risk of malocclusions. Methods Six databases were systematically searched to the end of October 2014. Observational and interventional studies were included. Breastfeeding was evaluated in three categories: (i) ever versus never; (ii) exclusive versus absence of exclusive; and (iii) longer periods versus shorter periods. All types of malocclusion were considered as the outcome. Pooled adjusted odds ratio and its 95% confidence interval (95%CI) were obtained from meta-analyses. Heterogeneity was assessed with both the Q-test and the I-square. Funnel plots and Egger's test were employed to assess publication bias. Results Forty-eight studies were included in the systematic review, and 41 were included in the overall meta-analysis (n = 27 023 participants). Subjects who were ever breastfed were less likely to develop malocclusions than those never breastfed (OR 0.34; 95% CI 0.24; 0.48), those who were exclusively breastfed presented lower risk to present malocclusion than those with absence of exclusive breastfeeding (OR 0.54; 95% CI 0.38; 0.77), and subjects longer breastfed were less likely to have malocclusions than those shorter breastfed (OR 0.40; 95% CI 0.29; 0.54). Conclusion Breastfeeding decreases the risk of malocclusions.