In the present study the diversity of HLA-A-B-DRB1*03:01 and HLA-DRB1*03:01-DRB3 haplotypes in the Croatian population was analyzed. The first tested group included 157 families in which at least one parent was positive for HLA-DRB1*03:01 allele. HLA-A-B-DRB1*03:01 haplotypes were determined by segregation analysis. The second group included 73 unrelated healthy subjects positive for HLA-DRB1*03:01 allele, who were further analyzed for polymorphism of HLA-DRB3 gene. All subjects were tested for HLA-A, -B and -DRB1 alleles by Polymerase Chain Reaction - Sequence Specific Probes (PCR-SSO) method, while HLA-DRB3 alleles were identified by Polymerase Chain Reaction - Sequence Specific Primers (PCR-SSP) method. The HLA-DRB1*03:01 allele exhibited strong linkage disequilibrium with HLA-B*08:01 allele, while the most frequent haplotype was HLA-A*01:01-B*08:01-DRB1*03:01 (47.8%). Two alleles were detected at HLA-DRB3 locus (DRB3*01:01:02 and DRB3*02:02:01:01; 67.1% and 32.9%, respectively). A total of 92.7% HLA-B*08:01 positive subjects were also positive for HLA-DRB3*01:01:02 allele (P<0.01). Combination of HLA-DRB1*03:01-DRB3 haplotype is associated with presence/absence of HLA-B*08:01 allele, while HLA-A alleles don't have any influence.