The scientists from the RCPTM research division Biologically active complexes and molecular magnets and Department of Inorganic Chemistry, Faculty of Science, Palacký University in Olomouc, lead by prof. RNDr. Zdeněk Trávníček, Ph.D. have achieved further significant advancement in the research of novel highly effective potential anticancer drugs. The national patent entitled “Platinum dichlorido complexes with halogenoderivatives of 7-azaindole, method of their preparation and use of these complexes as drugs in antitumour therapy” (CZ 303417 B6, inventors: Pavel Štarha, Igor Popa, Zdeněk Trávníček) protects the preparative method and possible application of the presented compounds in the treatment of cancer. Significant antitumour activity of the patented compounds was proved on two human cancer cell lines, i.e. human osteosarcoma (HOS) and breast adenocarcinoma (MCF7). In the in vitro study, it was found out that the presented compounds were significantly more cytotoxic on the mentioned cell lines than cisplatin, i.e. commonly used platinum-based anticancer drug. The obtained promising results are motivating for further and more advanced study of the mechanisms of action on the molecular level and in in vivo models.