Methods and pharmaceutical compositions for treating viral infections, by administering certain 2-aryl-benzothiazole or 2-heteroaryl-benzothiazole derivative compounds in therapeutically effective amounts are disclosed. Methods of using the compounds and pharmaceutical compositions thereof are also disclosed. In particular, the treatment and prophylaxis of viral infections such as caused by flavivirus is disclosed, i.e., including but not limited to, Dengue virus, West Nile virus, yellow fever virus, Japanese encephalitis virus, and tick-borne encephalitis virus.