context: genotyping of single nucleotide polymorphism (snp c/t-13910) located upstream of the lactase gene is used to determine adult-type hypolactasia/lactase persistence in north-european caucasian subjects. the applicability of this polymorphism has been studied by comparing it with the standard diagnostic methods in different populations. objective: to compare the lactose hydrogen breath test with the genetic test in a sample of the colombian caribbean population. methods: lactose hydrogen breath test and genotyping of snp c/t-13910 were applied to 128 healthy individuals (mean age 35 ± 1). a positive lactose hydrogen breath test was indicative of hypolactasia. genotyping was done using polymerase chain reaction/restriction fragment length polymorphism. the kappa index was used to establish agreement between the two methods. results: seventy-six subjects (59%) were lactose-maldigesters (hypolactasia) and 52 subjects (41%) were lactose-digesters (lactase persistence). the frequencies of the cc, ct and tt genotypes were 80%, 20% and 0%, respectively. genotyping had 97% sensitivity and 46% specificity. the kappa index = 0.473 indicates moderate agreement between the genotyping of snp c/t-13910 and the lactose hydrogen breath test. conclusion: the moderate agreement indicates that the genotyping of the snp c/t-13910 is not applicable to determine adult-type hypolactasia/lactase persistence in the population participating in this study.