Field trials comparing commercially available repellent formulations containing picaridin (1-piperidinecarboxylate acid, 2-(2-hydroxyethyl)-1-methylpropylester) and deet (N,N-diethyl-3-methylbenzamide) against mosquitoes in Northern Territory, Australia, were conducted. Three repellents were compared: Autan Repel containing 9.3% picaridin, RID® containing 10% deet, and Bushman Ultra™ containing 80% deet in a gel. The predominant mosquito species collected were Culex annulirostris Skuse (63.2%), Ochlerotatus normanensis (Taylor) (19.6%), and Anopheles meraukensis Venhuis (8.6%). Autan Repel provided >95% protection against all mosquitoes for 2 h, RID for 7 h, and Bushman for >8 h. Against Cx. annulirostris, Autan Repel provided >95% protection for 5 h, RID for 7 h, and Bushman for >8 h. The study showed that both deet formulations provided significantly better protection against mosquitoes than picaridin (Autan Repel). All 3 repellents provided good protection against Cx. annulirostris, an important vector of arboviruses in Australia.