Objective: Human immune recognition of self and foreign is partially controlled by a set of genes in the human leukocyte antigen complex (HLA). HLA is the most polymorphic region in the human genome, and it is used to assure compatibility between donor and recipient for hematopoietic stem cell transplantation. There are six "classical" HLA genes encoding highly polymorphic loci: HLA-A, B, and C (Class I major histocompatibility complex), and HLA DR, DQ, and DP (Class II). This study aims to quantify the frequency of HLA A, B, C, DRB1, and DQB1 alleles taken in a transplant center in the northeastern part of Mexico. Methods: Descriptive and retrospective data of HLA typing by polymerase chain reactions-SSP for class I and II HLA in our Institution were analyzed. Tests for HLA-A, B, C, DRB1, and DQB1 were performed in 1614 patients. The number of haplotypes found was 726. Results: The most common combinations were A*02, B*35, C*04, DRB1*08, and DQB1*04, which were observed 38 times (5.2%). Conclusion: The most frequent HLA alleles were HLA-A2 and HLA-DQ 03, respectively, with a frequency of 0.2961 and 0.2758.