PURPOSE: to check whether there is a predominance of deleterious oral habits in different facial typesand further study of the relationship between harmful oral habits and dental occlusion. METHOD: we analyzed 307 cases of patients between 2 and 59-year old of both genders, referred to the outpatient clinic of CEFAC Institute. Were we registered medical records of deleterious oral habits, dental occlusion, facial type, gender and age. RESULTS: we observed that the following habits are most prevalent: pacifier (125 subjects), gnashing teeth (115 subjects) and bottle (102 individuals). Among the comparisons, the ones who showed statistical significance was the presence of pacifier use in the group from 9 to 12 years, compared to 6 to 9 years (p=0.0269), presence of habit of gnashing teeth in the group from 3 to 6 years when compared to more than 20 years (p = 0.0393), presence of the habit of gnashing teeth in the group of dental occlusion class I compared to class III (p = 0.0128) and presence dental occlusion class I in females compared to males (p=0.0177). CONCLUSION: there is no relationship between harmful oral habits and facial typology. However, there is a relationship between the harmful oral habit of grinding the teeth with Angle class I dental occlusion.