Background: Dengue virus (DENV) currently infects 50-100 million people/year, causing about 500,000 cases of severe complications (dengue haemorrhagic fever; dengue shock syndrome) and 20-25,000 deaths. From USD 1.35 billions/year Brazil spends in dengue, USD one billion is allocated to the vector control programme. All attempts at control of the mosquito vector have systematically failed, and there is no specific treatment or vaccine currently available. Homeopathy has a long record of success in the treatment of epidemic diseases. Although recent experiences pointed to the possible efficacy of homeopathic prophylaxis and treatment in dengue, with low cost, satisfactory acceptance by the targeted population, and lack of adverse events, clinical trials reported controversial results.