Objective: To examine the correlation of lactase persistence phenotype with genotype in Omani adults. Methods: Lactase persistence phenotype was tested by hydrogen breath test in 52 Omani Adults using the Micro H2 analyzer. Results were checked against genotyping using direct DNA sequencing. Results: Forty one individuals with C/C-13910 and T/T-13915 genotypes had positive breath tests (≥20 ppm); while eight of nine individuals with T/C-13910 or T/G-13915 genotypes had negative breath tests (<20 ppm) and two subjects were non-hydrogen producers. The agreement between phenotype and genotype using Kappa value was very good (0.93). Conclusion: Genotyping both T/C-13910 and T/G-13915 alleles can be used to assist diagnosis and predict lactose intolerance in the Omani population.