We conducted laboratory tests to assess the sensitivity to the insect repellent 1‐piperidinecarboxylic acid, 2‐(2‐hydroxyethyl)‐, 1‐methylpropylester (known as KBR 3023 or Picaridin, trade name Bayrepel®) of West African strains of the yellow fever mosquito Aedes aegypti and of malaria vectors of the Anopheles gambiae complex, in comparison with the standard repellent N, N‐diethyl‐3‐methyl‐benzamide (DEET). Test mosquitoes were exposed according to a 'separate arms' protocol to logarithmic dose increments applied on one arm of human subjects to evaluate the relative potency, and the median effective dosages (ED50 and ED90). According to a logistic regression model fitted to the experimental data, the dose–response relationship for the two repellents was the same within each species, thus pooled ED values were assessed for each mosquito separately …