Objetive: Associate direct breastfeeding, use of bottle in infants and oral habits, with occlusal characteristics in preschool stage of four educational institutions. Methodology: A transversal descriptive study was performed with 309 children from 3 to 5 years old, from four educational institutions in Lima-Peru. Questionnaires were given to the parents for information gathering about direct breastfeeding, use of bottle and parafunctional oral habits that their children presented. The following variables were evaluated: presence or absence of anterior open bite, crossbite, type of arch according to Baume, overjet, overbite, digital suction, lip suction and use of pacifier. Square Chi test and Fisher exact test were performed to associate direct breastfeeding, use of bottle in infants and oral habits, with occlusal characteristics. Results: Significant association (p < 0.05) was found among oral habits with occlusal alterations. 37.1% of preschool children that had lip suction presented anterior open bite and 57.1% type II arch; 47.4% of preschool children that had digital suction presented increased overjet; 51.1% of preschool children that used pacifier presented type II arch. 75.8% of preschool children that did not have any habit presented normal overjet and 66.5% normal overbite. Significant association (p < 0.05) was found between feeding type with occlusal alterations. 75.3% of preschool children that were breastfed presented normal overjet and 64.8% normal overbite; 36.6% of preschool children that were not breastfed presented increased overjet and 34.6% anterior open bite; 10.6% of preschool children that used bottle presented anterior open bite. The association between age with anterior open bite, crossbite and arch type was not significant, (p=0.969, p=0.207, p=0.529). Neither the association between gender anterior open bite, crossbite and arch type, (p=0.243, p=0.705, p=0.655). Conclusions: Suction habits and use of pacifier can produce alterations in occlusion. Moreover, it was revealed that the absence of breastfeeding during the first months of life could limit the orofacial development which would cause future alterations.