AbstractA series of six highly lipophilic Cp‐substituted molybdenocenes bearing different bioactive chelating ligands was synthesized and characterized by NMR spectroscopy, mass spectrometry and X‐ray crystallography. In vitro experiments showed a greatly increased cytotoxic potency when compared to the non‐Cp‐substituted counterparts. In vivo experiments performed with the dichlorido precursor, (Ph₂C−Cp)₂MoCl₂ and the in vitro most active complex, containing the thioflavone ligand, showed an inhibition of tumour growth. Proteomic studies on the same two compounds demonstrated a significant regulation of tubulin‐associated and mitochondrial inner membrane proteins for both compounds and a strong metabolic effect of the thioflavone containing complex.