The invention concerns a method for the targeted selection of a double-stranded ribonucleic acid (dsRNA) consisting of two single strands that exhibits increased effectiveness in inhibiting the expression of a target gene by means of RNA interference, whereby the sequences of the single strands of the dsRNA are selected in such a way that on both ends of the dsRNA the last complementary nucleotide pair is a G-C, or at least two of the last four complementary nucleotide pairs are G-C pairs; whereby the dsRNA exhibits a single-stranded overhang consisting of 1 to 4 unpaired nucleotides at the first end, and no overhang at the second end; whereby the unpaired nucleotide of the single-stranded overhang that is directly adjacent to the last complementary nucleotide pair contains a purine base.