Bone Marrow Transplant (BMT) is a lifesaving procedure for several diseases. Histocompatibility between host and donor is crucial for the success of this therapy. Since human leukocyte antigen (HLA) genes are the most polymorphic in humans, a foreknowledge of their frequencies and a vast register of volunteer donors are important for patients who need an unrelated donor. This research evaluated data from 3500 HLA-typed donors using PCR-SSP (One Lambda ABDRX kits, low/medium resolution). The allele and haplotype frequencies were calculated from the donor HLA typings. Among the total sample we observed that the allelic groups HLA-A*02, -B*35, and -DRB1*11 had frequencies of 0.228, 0.112, and 0.125, respectively. The haplotype HLA-A*01-B*08-DRB1*03 was the most frequent (0.024). We also compared our results with another study conducted in a Northeastern Brazilian population. The identification of the most common allelic groups and haplotypes is of great interest, not only to know the HLA composition of the population but also to search for the best HLA match for a transplant. However, the search for the perfect match depends on the eventual registration of every specific donor in the national registers for bone marrow donation.