Objectives: To assess the prevalence and severity of dental caries amongst Egyptian adolescents and the prevalence of carious lesions treatable through the atraumatic restorative treatment (ART) approach. Subjects and Methods: Using a convenient sample procedure, two secondary schools with a dental clinic were selected (967 students, average age: 13.7 ± 0.8 years, range: 12–15). Dental caries was diagnosed using the ART caries criteria, and plaque and calculus were assessed using the Green and Vermillion criteria amongst students grades 1–3 in the dental clinic by 3 calibrated examiners. The effect of the independent variables gender, age, tooth surface, jaw side (left or right) and type of jaw (mandible/maxilla) on dependent caries experience variables and D2 and D3 variables were tested using ANOVA. Results: The prevalence of dental caries including enamel lesion (D2MFT) amongst the 967 students was 51.4% and that of dental caries excluding enamel lesions (D3MFT) was 38.1%. The mean D2MFT and D3MFT scores were 1.5 and 0.8, respectively. The percentage of teeth filled and extracted was low. Female students had statistically significantly higher mean D3MFT/S and D2MFT/S scores than males (p < 0.0001). The prevalence of cavitated carious lesions (D3) treatable through ART was 48% for score 2 and 28% for score 3. Conclusions: Most of the cavitated lesions were found untreated despite the presence of a dental clinic and a dentist on the school premises. The majority of cavitated lesions without pulp involvement could be treated using the preventive and restorative components of the ART approach.