Benzylamide 5'-32P-oligonucleotide derivatives were shown to penetrate into mice organism when administered by various routes; intranasally, per os, intravaginally and per rectum. In all cases, the compounds are rapidly accumulated in blood and guts. Analysis of the radioactive material from blood and pancreas revealed intact oligonucleotides. Although concentrations of oligonucleotides in tissues differ considerably by the various methods of administration, the efficiency of delivery is sufficient to consider all the routes as being of therapeutic value. Dose effect on the efficiency of oligonucleotide penetration into mice suggests the transport to be a saturable process. Application of an oligonucleotide lotion on mice ear helices results in reproducible accumulation of radioactivity in the animal tissues. Effectiveness of oligonucleotide delivery into mouse through skin can be improved by using electrophoretic procedure.