This study has shown that dandelion extracts can inhibit both A/PR/8/34 and WSN (H1N1) influenza viruses by inhibiting viral nucleoprotein synthesis and polymerase activity. These results lead to further investigation about characterization of active compounds and their specific mechanism against influenza virus. Given the urgent need for new and abundantly available anti-influenza drugs, dandelion extracts appear to be a promising option as a replacement or supplemental strategy to cur-rently available anti-influenza therapies.