Background: Molar Incisor hypomineralizationis an enamel defect caused by a systemic disturbance that could have occurred during child development. It affects one or more permanent molars with or without incisors involvement. Many factors could contribute in presence of MIH, for instance, chronic illnesses during pregnancy or during the first three of childhood. However, the actual etiological factor has not been determined yet. The study aim is to evaluate the knowledge and the perception on MIH among GDPs in KSA.Methods: This is a descriptive cross sectional study, web-based survey conducted on 500 participants. An online questionnaire was distributed to all GDPs working in KSA. The data analysis done using SPSS version 23 (IBM Crop USA).Results: We found that the majority of GDPs perceptions were found that 64.7% had the thought that MIH is a public problem next to dental caries. When we assessed the perceptions about diagnosis MIH, it was found that 35.7% not confident and 58.3% showed some confidence in diagnosing the same. The dentists’ confidence about treating MIH showed that 49.5% were confident.Conclusions: We found that the majority of GDPs have a good knowledge. The perception was found that 64.7% had the thought that MIH is a public problem next to dental caries. When we assessed the perceptions about diagnosis MIH, it was found that 58.3% showed some confidence in diagnosing the same. The dentists’ confidence about treating MIH showed that 49.5% were confident.