Purpose: The purpose of this study was to evaluate the prevalence and severity of molar incisor hypomineralization (MIH) among schoolchildren in Dubai, UAE.Methods: A randomized cluster sample of 342 eight to 12-year-old schoolchildren had their permanent first molars and incisors evaluated for prevalence and severity of MIH using the European Academy of Paediatric Dentistry criteria.Results: The prevalence of MIH in Dubai was found to be 27.2 percent and was significantly higher in girls (32.6%) compared to boys (18.1%;P=0.002). The prevalence of molar hypomineralization (MH) was higher than MIH: of the 27.2 percent diagnosed children, 65.6 percent had only MH while 34.4 percent had MIH. MH prevalence in maxillary molars was 20.8 percent, significantly higher than 14.6 percent in mandibular molars (P≤0.005). Almost nine percent of maxillary incisors were affected by MIH compared to 0.9 percent of mandibular incisors (P≤0.001). The presence of demarcated opacities was significantly higher in females than males (P =0.002). Fifty-three percent of the children with MIH had mild defects, 17 percent had moderate defects, and 30 percent had severe defects.Conclusions: Despite the high prevalence of MIH in schoolchildren in Dubai, the severity was mild. The prevalence of MIH and MH was significantly related to sex and location of tooth in the oral cavity.