Satellite DNA, whose monomers form long arrays of tandem repeat ranging from hundreds or thousands of copies to several million base pairs, makes up at least 10% of the human genome. Application of new methods of sequencing and bioinformatics analysis opens the way to investigate the organization and functioning of human satellite DNA and contributes to the revision of the long-standing view about this part of the genome as “junk DNA.” One of the important features of satellite DNA is its participation in structural rearrangements in the human karyotype. This review examines the mechanisms of participation of satellite DNA in the formation of structural rearrangements, as well as the nature of transcription of tandem repeats in structural rearrangements in the karyotype of normal and tumor cells.