Background: This study aimed to assess caries prevalence and experience among 11 to 14 years, school children, analyze demographic, socioeconomic, personal and professional dental care in relation to untreated carious lesions, and evaluates the effect of decayed teeth on early adolescents' oral health-related quality of life (OHRQoL). Methods: A cross-sectional analytical investigation was conducted on 1020 preparatory schoolchildren selected on the basis of a multistage sampling technique. Caries status of the participants detected via recording their caries experience and untreated cavities using DMFT and DT indices. OHRQoL was determined using a validated Arabic CPQ 11-14 short-form questionnaire. Statistical methods for descriptive analysis, chi-square test, Independent-Samples t test and one-way analysis of variance (ANOVA) were used. Multivariate Poisson regression analysis through a hierarchical approach was used to detect the influence of independent variables on DT scores. To declare the association between independent variables and QoL, a step-by-step, multivariate regression analysis was conducted. Results: The average scores of DMFT and DT in this study were 2.97 ± 1.29 and 1.66 ± 1.24. Poisson regression analysis demonstrated that early adolescents whom their mothers with a lower level of education and of low socioeconomic status were 1.41 and 1.27 times respectively had higher DT scores when compared with their peers. Untreated cavities affected mainly by mother education, school type, family income, and regular dental appointments. Children with DMFT≤3) or DT = 0 recorded a statistically significant lower CPQ 11-14 average score (p<0.01) and (p<0.0001) respectively. Conclusions: Untreated carious cavities and caries experience were associated with lower socioeconomic, maternal education andl ess frequent tooth brushing. Untreated carious cavities have a significant negative impact on schoolchildren's QoL.