Extraction of Am and Eu from HNO3 media by phosphorylated calix-arenes in m-nitrobenzotrifluoride was studied and the following was established:• organophosphorus substituents affect the extraction properties of calix-arenes in the same manner as in the case of routine organophosphorus compounds; • calix[4]phosphine oxides and calix[4]phosphinic acid demonstrate considerable cooperative effect and extract Am and Eu about 100-times more efficient than corresponding monophosphoryl compounds; • calix[4]tetraphosphine oxides form disolvates with Am and Eu; • transfer from phosphorylated calix[4] to calix[6]arenes, i.e. increase in number of donor P=O groups, has practically no influence on extraction of Am and Eu; • only calix[4]carbamoyl extracts Am better than Eu; • as to extraction ability, calix[4]dioxide and calix[4]carbamoyl are close to conventional diphosphine dioxides and carbamoylphosphine oxides. © 2002 Atomic Energy Society of Japan.