We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 684 Mexicans from the state of Coahuila living in Saltillo (N = 72), Torreón (N = 396) and rural communities (N = 216), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Coahuila include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Coahuila are European (49.72 ± 4.18% by ML; 37.49% of European haplotypes) and Native American (45.01 ± 2.69% by ML; 42.98% of Native American haplotypes), while African genetic component is less apparent (5.27 ± 1.88% by ML; 9.92% of African haplotypes). Copyright © 2019 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.