Introduction: Discovery of the human leukocyte antigens in 1958 greatly influenced the development and progress of medicine as a whole, especially the transplantation, which is closely connected with HLA. It can be said that it is the most polymorphic genetic system in humans because it contains a very large number of loci and alleles at these loci. The main role of HLA is to differentiate foreign from own cells and to trigger an immune response as a defense against a foreign antigen. The whole system is divided into three classes: HLA I, HLA II and HLA III. The HLA class I is crucial for the endogenous pathway of antigen presentation, while the HLA class II is responsible for the exogenous pathway of antigen presentation. HLA system allele determination can be performed serologically and molecularly. Objective: Investigate the association of certain alleles of the HLA system with the occurrence of neurological diseases. Methods: Results of this study were obtained by the molecular method of PCR-SSO. The research was conducted in the Tissue Typing Laboratory at the Clinical Hospital Center Split. Conclusion: Neurological diseases are a topic that is complex to talk about, but this research still came to some conclusions. The association of individual alleles with certain neurological diseases has been observed, and the obtained results agree with other scientific papers conducted in the world. In order to speak with certainty about a significant correlation, it is necessary to repeat the research on a larger number of respondents.