This study investigates the different Human Leukocyte Antigen (HLA) genotypes and their possible associations with both disease and behavior, specifically by describing significant associations between particular HLA genotypes and occurrence of intentional violent death. A de-identified dataset of n = 216,426 deceased American organ donors was analyzed for all possible genotypes by comparing the Independent Variable (Each specific HLA genotype vs. remainder of sample, non-genotype) on the Dependent Variable (Intentional Violent vs. Non-violent death). For HLA-A, 17 heterozygotes were significantly associated with increased occurrence of intentional violent death, with heightened prevalence for HLA-A2, HLA-A23, HLA-A30, HLA-A68, and HLA-A74 alleles. For HLA-B, 32 heterozygotes were significant, 25 of which (e.g., HLA-B7, HLA-B8, HLA-B35, HLA-B44, and HLA-B53) exhibited heightened prevalence of violent death. For HLA-BW, homozygotes had significantly increased odds ratios for intentional violent death. For HLA-DRB1, 19 heterozygotes were significant, with heightened prevalence only for the HLA-DRB1-4 allele. There were no racial differences in risk for the significant HLA-A and HLA-B genotypes. These exploratory, not necessarily causal, results provide the first indications of possible HLA-aggression associations in humans, supporting animal models.