Aminoacyl-tRNA synthetases (aaRS) are essential proteins of all living organisms. It is known that they ensure the fidelity of transfer of genetic information from the DNA into the protein. Not far away it occurred that their role is not confined to catalyze the attachment of amino acids to transfer RNAs and thereby establish the rules of genetic code by virtue of matching the nucleotide triplet of anticodon with cognate amino acid. aaRSs are also engaged in the other crucial cellular processes. So the disturbance of function of any of them often causes serious disorders. Therefore this proteins could be an attractive target of drugs, not only against the mentioned illnesses but also against bacterial, fungal and parasitic infections. Constant progress on this field makes aaRSs still an interesting object of researches.