Double Pu(V) and Np(V) acetates of the compositions BaPuO2Ac3·2H2O and SrAnO2Ac3·3H2O with An = Pu and Np were synthesized in a well-crystallized form. In the dry state the compounds are stable in prolonged storage and are not hygroscopic. The plutonyl(V) and neptunyl(V) salts of the similar composition are isostructural. The IR spectra of the compounds were measured, and their behavior in heating was studied.