Expecting a significant breakthrough in the diagnosis of complex disorders of neuropsychiatric background, intensive efforts are taking place to establish genetic markers correlated with these disorders. During the last decade, this research was focused on code regions connected with neurotransmission and metabolism of catecholamines. Nowadays big diagnostic expectations are associated with sequences of STR type, which are widespread throughout the genome. These microsatellite sequences do not code proteins, but may have function of regulatory elements in the process of gene transcription and expression. One of these is polymorphic TH01 locus with TCAT tetranucleotide repetitive motive. It is located in chromosomal position 11p15 in the first intron of the tyrosine hydroxylase gene (TH). We examined the existence of the association between polymorphism of TH01 marker and schizophrenia. The results of statistical comparative analysis between neuropsychiatric patients from Poland and their regionally matched healthy subjects were presented.