Objectives: To quantify the prevalence of Molar Incisor Hypomineralization (MIH) in the canton of Geneva, Switzerland. Study design: Thirty-eight dentists of the state school dental services were trained to detect and classify MIH cases. All children (32,142) from age 4 to 12 were examined during the annual dental screening offered by the state. Cases were scored as mild, moderate or severe. Results: The prevalence of hypomineralizations was found to be 7.45% when all hypomineralized teeth were taken into consideration. MIH cases were found to be at 6.6%. Out of the MIH cases, 51% scored as mild, 36% as moderate and 13% as severe. Conclusion: The mean prevalence of MIH in Geneva school children was found to be 6.6%. This seems to be lower than the European and the global average. However, with almost half cases being moderate or severe, asserting a proper management protocol is necessary.