Toxicity of three mosquito oviposition repellents, N,N-diethyl-3-methylbenzamide (AI3-22542 or deet), AI3-35765, and AI3-37220 to 6 aquatic nontarget invertebrates, was evaluated in the laboratory. The 24-h LC₅₀ values for Cypricercus sp. (Ostracoda), Moina sp. (Cladocera), Eucyclops agilis Koch (Copepoda), Strelkovimermis spiculatus Poinar & Camino (Nematoda), first- and fourth-instar Toxorhynchites amboinensis Doleschall larvae (Diptera), and fourth-instar Chironomus decorus Johannsen larvae (Diptera) ranged from 0.012 to 0.127% or 120 to 1,270 ppm. Cypricercus sp., Moina sp., E. agilis, first-instar Tx. amboinensis and fourth-instar C. decorus were generally more sensitive to the test repellents than male and female S. spiculatus and fourth-instar Tx. amboinensis. Male S. spiculatus was more sensitive to the repellents than its female and this was probably because of the smaller body size of the male. All invertebrates were generally more sensitive to AI3-37220 than to deet and AI3-35765. The experimental repellents were considered safe to the aquatic nontarget organisms when employed as oviposition repellents for Aedes albopicus (Skuse) mosquitoes.