This report describes the epidemiology of mosquito-borne disease in Australia for the mosquito-borne disease season 1 July 2006 to 30 June 2007, which was moderately low compared to previous seasons. Ross River virus (RRV) infections (55%), Barmah Forest virus (BFV) infections (29%) and overseas acquired malaria (11%) were the most common mosquito-borne diseases reported in 2006-07. The number, proportion and rate of national BFV notifications were the second highest on record since 1998-99. The Northern Territory reported the highest BFV notification rate this season. BFV notification rates were the highest in the 40-59 year age groups when compared to other age groups. The number, proportion and rate of RRV notifications were moderately low this season compared with previous seasons. The highest RRV rate was reported by Western Australia from the Kimberley region. The highest age-specific RRV notification rate was observed in the 40-59 year age groups. Locally acquired dengue virus notifications were low this season compared to previous seasons, with a small outbreak of dengue serotype 3 in 39 cases confined to the greater Townsville region. There were 640 notifications of malaria in 2006-07 of which none were reported as locally acquired. This was the third highest number of malaria notifications since 2001. Plasmodium falciparum was reported as the infecting species in 47% of the malaria notifications and Plasmodium vivax for 40% of cases. Young adolescents and adults in the 15-29 year age group had the highest number of cases accounting for 32% of notifications. Sentinel chicken surveillance data for flaviviruses and sentinel pig surveillance data for Japanese encephalitis virus are also reported.