This review deals with the possible connection between Human Leukocyte Antigen (HLA) molecules and metal disorders, which are represented by schizophrenia, autism spectrum disorders, bipolar disorder and post-traumatic stress disorder. The article tries to summarize alleles that are known to be associated with mental disorders. Furthermore, the paper informs of the mechanisms by which the alleles influence origin and development of the above-mentioned disorders. Although there are many studies dedicated to this topic, there has not been a satisfactory explanation of the way HLA molecules are involved in the etiology of mental disorders yet.