The prevalence of ocular allergy varies according to the population and location of the study. Severe forms of ocular allergy are associated with compromised quality of life. In this study, we aimed to evaluate the application of the Brazilian-Portuguese version of the Quality of Life in Children with Keratoconjunctivitis questionnaire to children and adolescents with different subtypes of allergic conjunctivitis. A total of 48 patients (aged 5-12 years) with allergic conjunctivitis were included in this study. They were enrolled and monitored at a specialized center. After the clinical appointment, the children responded to the questionnaire on two occasions at an interval of 30 days. Individual scores (ranging from 0 to 3) of the 16 items were added. The Brazilian-Portuguese version of the Quality of Life in Children with Keratoconjunctivitis questionnaire demonstrated good translation, adaptation, and intellectual properties, with substantial internal consistency (Cronbach's α coefficient = 0.702). There was no significant difference between the responses of the two interviews, revealing good reproducibility. The moderate/severe forms of allergic conjunctivitis had significantly higher quality of life scores (indicating a poorer quality of life) than the mild forms. The Brazilian-Portuguese version of the Quality of Life in Children with Keratoconjunctivitis proved to be quick, reliable, and reproducible for assessing the quality of life in children with allergic conjunctivitis. However, its ability to detect changes resulting from symptom aggravation or treatment needs to be further evaluated.