Objectives: The aim of the work is to observe the differences in the representation of alleles in patients with psoriatic arthritis compared to the control group and to show the alleles that appear with greater frequency in subjects with PsA. Material and methods: Due to the lack of definitive laboratory tests for psoriatic arthritis, HLA typing has proven to be of great use considering the association of PsA with certain alleles of the HLA system. To determine the alleles of the HLA locus, molecular methods (PCR-SSO, PCR-SSP) were used in routine work on 105 patients referred by a rheumatologist. Results: By comparing the frequency of HLA locus alleles in patients with PsA compared to the control group, an increased frequency of HLA-A*32 and HLA-A*02 alleles was observed in patients. The HLA-B*08, HLA-B*13 and HLA-B*57 alleles show a statistically significant frequency in patients with PsA, while the most frequent allele was the HLA-C*06 allele and represents a risk factor for psoriatic arthritis. Different results in the allele representation of the HLA-DRB1 locus may be relevant for the modulation of clinical expression. Conclusion: PsA is a clinically heterogeneous disease. The obtained results indicate the complexity of the HLA system, which is not only the foundation and the main link in the field of transplant medicine, but thanks to the latest methods of molecular biology (PCR, NGS) and the main starting point in determining the genetic predisposition for several diseases. There is still a need for further and larger genetic studies, within and beyond the HLA region, to reach firmer conclusions regarding psoriatic arthritis.