Structure, mechanism of action and biological role of steroidogenic factor-1 (SF-1), in particu- lar the significance of this factor for the normal function of the adrenal cortex, have been presented. SF-1 is a transcription factor, classified to an orphan nuclear receptor family, which interacts with the specific nucleotide sequence within promoters of the target genes, including those encoding proteins participating in the synthesis or transport of steroid hormones or their precursors in the cell. Structure of the SF-1 gene, transcript and protein was presented as well as the regulation of SF-1 expression and transcriptional activity of the protein product of the gene. Major genes regulated by SF-1 were mentioned and many of them characterized. The role of SF-1 in the origin of adrenocortical carcinomas and prospects of SF-1 application in the treatment of the diseases of the adrenal cortex were discussed.