Selected monocarboxylic esters of aliphatic diols that contained an alicyclic group in the acyl portion of the molecule were effective repellents for Aedes aegypti, Anopheles quadrimaculatus and An. albimanus when tested on cloth. Although 25 of the esters provided greater than 21 days of protection against all 3 species, the repellent potency of the 143 hydroxyesters that were tested was found to vary with mosquito species. Anopheles quadrimaculatus was especially susceptible to this type of structure; 112 of the esters provided greater than 21 days of protection and 56 provided greater than 100 days of protection. Aedes aegypti was moderately susceptible to these repellents; 72 esters provided greater than 21 days of protection. Anopheles albimanus was the most difficult mosquito to repel. Only 29 of the esters provided greater than 21 days of protection.