A calf-baited trap was designed and used to capture Anopheles albimanus adults in El Salvador. Daily collections during a 1-yr study showed that this type of trap was useful in sampling mosquitoes for estimating population densities and providing live, healthy adults for biological assays from areas where other methods of collection were not possible. Capturing mosquitoes with traps generally proved to be a more efficient method than the standard method of capturing adults from stables.