Background <p>Molar Incisor Hypomineralization (MIH) is a qualitative enamel defect affecting first permanent molars often involving incisors. It presents clinical challenges including hypersensitivity, rapid caries, and restorative difficulties. Though its etiology is unclear, systemic and environmental factors have been implicated.</p> Objective <p>This study aimed to determine the prevalence and associated factors of MIH and to assess the risk factors.</p> Methods <p>A cross-sectional study was conducted on children aged 6–12 years in İzmir, Türkiye. Among 700 children examined, 50 diagnosed with MIH were included in the case group, while 50 healthy children formed the control group. Parental interviews assessed sociodemographic, prenatal, perinatal, postnatal factor. Biochemical parameters were analyzed appropriate statistical tests.</p> Results <p>MIH prevalence was 12% and 76% had severe defects (MIH-2), and 24% had mild opacities (MIH-1). Significant associations were observed with socioeconomic status, maternal employment, birth weight, antibiotic use and respiratory infections (<i>p</i> &lt; 0.005). Exclusive breastfeeding duration was longer in controls (<i>p</i> = 0.020).</p> Conclusion <p>MIH is a multifactorial condition influenced by systemic and environmental factors. Early diagnosis and prevention are essential. Longer breastfeeding duration may offer a protective effect. Larger longitudinal studies are needed to better understand associated factor of MIH.</p>