Many mitochondrial genes have been transferred to the nucleus in course of evolution. The products of expression of these genes, being still necessary for organelle function, are imported there from the cytosol. Molecular mechanisms of protein import are studied much deeper than those of nucleic acids. The latter, it seems to us, retards the development of mitochondrial genome editing technologies. In this review, we describe mechanisms of DNA, RNA, and protein import into mitochondria of different eukaryotes. The description is given for the natural processes, as well as for artificial targeting of macromolecules into mitochondria for therapy. Also, we discuss different approaches to introduce changes into the mitochondrial DNA sequence.