Abstract: The present invention relates to novel derivatives of 2'-deoxyuridine substituted in the 5-, 3'- or 5'-position by .alpha.-aminoacyl groups, to a process for their preparation and the drugs in which they are present.These derivatives have the following general formula: ##STR1## in which R is selected from an alkyl or alkenyl radical having from 1 to 4 carbon atoms, an aryl radical or a halogen, it being possible for said alkyl, alkenyl and aryl radicals to contain at least one halogen substituent, and a radical of the formula --NH--R.sub.1, in which R.sub.1 is an amino acid residue or a peptide residue containing from 2 to 6 amino acids; andR' and R" are selected from a hydroxyl radical and a radical of the formula --NH--R.sub.1, in which R.sub.1 is as defined above,with the proviso that R' and R" are not simultaneously --NH--R.sub.1 and that, when R is --NH--R.sub.1, R' and R" are simultaneously a hydroxyl group.Application: treatment of cancers and viral infections.