Considering the importance of parental attitudes and their influence on children's oral health, it is important to know which characteristics may impact it. The aim of this population study was to evaluate the impact of the parental sociodemographic characteristics on the oral health-related quality of life (OHRQoL) of preschool children from southeastern Brazil. A population-based study was conducted with a sample of 321 children aged 2 to 5years old who underwent a calibrated clinical oral examination to assess oral health status and their parents were asked to answer the two following questionnaires: (1) sociodemographic conditions and (2) Brazilian version of the Early Childhood Oral Health Impact Scale (B-ECOHIS). Descriptive analysis, Mann-Whitney and Kruskal-Wallis tests and adjusted Poisson regression models were used. Younger mothers (RP: 1.47; 95% CI: 1.11-1.95), lower household income (RP: 1.47; 95% CI: 1.11-1.96) and the presence of dental caries (RP: 2.28; 95% CI: 1.74-3.0) were more likely to have a negative impact on the OHRQoL B-ECOHIS total scores (P < 0.01). The characteristics of mothers, such as age, schooling and salary, influenced the mean B-ECOHIS total score; however, paternal attributes were not associated with a negative impact on the children's quality of life. Also, dental caries and household income influenced the children's oral health-related quality of life.