Phosphate derivatives of AZT esterified with a carbohydrate (D-glucose, D-mannose, and ethyl D-mannopyranoside) and a hexadecyl chain were prepared from glucose 6-phosphate and D-mannose precursors. The P-31 NMR study of the mannosyl phosphotriester series in the presence of large unilamellar vesicles demonstrated either an interaction with the external lipid layer or a transmembrane transport into the intravesicular interface. The antiviral activity, measured by the inhibition of cytopathogenicity on different infected cells and of reverse transcriptase activity in the supernatant of cultures, appeared to be comparable to that of AZT, in the micromolar range.