AbstractHLA‐A, ‐B, ‐C, ‐DR, and ‐DQ typings of the Schmiedeleut Hutterites of South Dakota were collected as part of an ongoing genetic‐epidemiologic study of HLA and fertility. A total of 1,082 individuals, including 852 married adults representative of the reproductive population of this isolate, were characterized for five‐locus HLA haplotypes. HLA‐A1, A2, A3, and A24 accounted for 75% of observed HLA‐A alleles and HLA‐B27, B35, B51, and B62 accounted for 55% of observed HLA‐B alleles. S‐leut Hutterites are derived from 68 or fewer ancestors. However, only 48 ancestral HLA haplotypes were observed and nine of these accounted for over 52% of the observed haplotypes. Measures of two‐locus linkage disequilibrium derived from these haplotypes indicated that one‐third to half of the observed HLA‐A/B, B/DR, and A/DR allele combinations exhibited highly statistically significant linkage disequilibrium. Allele and haplotype frequencies did not differ between males and females. Recombination rates of 0.004% and 0.005% between HLA‐A and ‐C and between HLA‐B and ‐DR, respectively, were observed. This HLA profile points out a paucity of HLA alleles and haplotypes in this population and marked linkage disequilibrium among the HLA allele