New technology by ICA for chemical generation of carbon dioxide (CO2) was evaluated in olfactometer and large outdoor cage tests against laboratory-reared Aedes aegypti for potential use in mosquito surveillance programs. The proprietary CO2 generation system consists of a poly-Tyvek sachet containing 2 solid ingredients. Activated sachets immediately react to generate and release predictable levels of CO2 over time. In noncompetitive olfactometer studies, a freshly activated sachet attracted an average +/- SE of 96.6 +/- 0.9% of the available mosquitoes compared with 20.2 +/- 6.5% for 5 ml/min CO2 released from a compressed gas cylinder. In competitive tests, the sachet attracted 92.4 +/- 1.2% compared with 0.9 +/- 0.5% for the compressed gas. In the olfactometer, aged sachets attracted >90% of the available mosquitoes up to 8 h and ca. 27% 1 wk after activation. In the large outdoor cages, traps baited with activated sachets captured 2.2-5.4 times as many mosquitoes as unbaited traps, depending on time of testing after activation.