Purpose: To assess the impact of pulp necrosis on the oral health-related quality of life (OHRQoL) of children with early childhood caries and their caregivers.<br/>Methods: A cross-sectional study was performed with a consecutive sample of children who were divided into three groups: (1) caries-free children; (2) with untreated carious lesions and without pulp necrosis; and (3) with untreated carious lesions and at least one tooth with pulp necrosis. Data were collected using a sociodemographic questionnaire, the Early Childhood Oral Health Impact Scale (ECOHIS) and a dental clinical examination using the International Caries Detection and Assessment System index. Descriptive statistics, Kruskal-Wallis tests, Mann-Whitney tests and Poisson regression were performed (P <0.05).<br/>Results: A total of 532 children and their legal guardians participated in the study. Children with pulp necrosis had a greater negative impact on the OHRQoL versus those with untreated carious lesions without pulp necrosis (ratio of unadjusted and adjusted rates [RR] = 1.59; 95 percent confidence interval [95% CI] = 1.36 to 1.86; P <0.001), as measured by the total ECOHIS score. in Group 3, four- and five-year-old children had a greater negative impact on the OHRQoL than two- and three-year-old peers (RR = 1.36; 95% CI = 1.08 to 1.72; P <0,001).<br/>Conclusion: The presence of pulp necrosis increased the negative impact on OHRQoL of children with untreated carious lesions and their guardians.