Objective: The aim of the study was to determine the prevalence of caries in first permanent molars (FPM) among children aged from 8 to 12 years.

Methodology: This cross-sectional study was performed from May to November 2014 on school-going children living in Dammam, Saudi Arabia. A total of 540 children aged between 8 and 12 years were randomly selected from different schools of Dammam, out of whom 322 were boys and 218 were girls. The number of carious FPM in each jaw was noted separately.

Results: The prevalence of caries in FPM among 540 examined children was found in 269 (49.8%). Among these 269 children, 109 (40.5%) children had only one carious molar, 75 (27.9%) children had caries in two molars, 43 (16%) children had three carious molars, and 42 (15.6%) children had caries in all four FPM. There was no statistically significant link between prevalence of carious FPM and gender. Caries prevalence with increase in age was found to be statistically significant (P-value= 0.00). Conclusion: Dental health care professionals should be concerned about the findings of nearly 50% untreated carious FPM. Multiple factors can contribute to the high prevalence such as socioeconomic status, culture, and easy access to cariogenic food. Irrespective of the exact cause, an early intervention by educating children in schools about the etiological factors and consequences of dental caries is highly desirable.