The present invention relates to a double-stranded ribonucleic acid (dsRNA) having a nucleotide sequence which is less that 30 nucleotides in length and which is substantially identical to at least a part of a 3'-untranslated region (3'-UTR) of a (+) strand RNA virus, such as HCV, as well as pharmaceutical compositions comprising the dsRNA, together with a pharmaceutically acceptable carrier. The pharmaceutical compositions are useful for treating infections and diseases caused by the replication or activity of the (+) strand RNA virus, as well as methods for inhibiting viral replication.