INTRODUCTION: Mosquito-borne diseases such as malaria and dengue fever result in significant morbidity and mortality in developing countries. Vector control is often the most effective strategy to prevent disease transmission and novel methods are required to complement existing insecticide-based strategies. Biological control uses natural predators or pathogens to kill mosquitoes or reduce their capacity to transmit disease. Bacteria such as Wolbachia have been proposed to have the potential to provide effective biological control of mosquitoes. AREAS COVERED: A review of the potential role of bacteria in the control of mosquito-borne diseases highlighting the advantages and disadvantages of each strategy. In particular, a comprehensive summary of the progress made using the bacterial endosymbiont Wolbachia for dengue control. EXPERT OPINION: Pathogenic bacteria such as Bti can be used to kill mosquito larvae and several endosymbiotic bacteria such as Asaia could be genetically transformed to alter the mosquito's ability to transmit pathogens. The endosymbiotic bacterium Wolbachia has been successfully introduced into the principal vector of dengue, Aedes aegypti, and induces a variety of phenotypic effects that are predicted to reduce dengue transmission. The release of Wolbachia-infected mosquitoes has been undertaken as part of preliminary trials to determine the applied use of this bacterium for mosquito-borne disease control.