A 6-month study was carried out in northcentral Venezuela to evaluate the efficiency of the CDC light trap and the updraft ultraviolet (UV) light trap combined with carbon dioxide (CO2) or 1-octen-3-ol (or both) and human baits to sample outdoor Anopheles aquasalis and Anopheles albimanus populations. The human baits caught far more mosquitoes than did any of the other trapping methods. Comparing each of the trapping methods to the human bait catches, UV light trap + CO2 gave a closer correspondence of the ratio of An. aquasalis to An. albimanus compared with the ratio found in human baits than did any of the other trapping methods. The mean parous rate was significantly lower in human bait catches than in all of the trapping methods except for An. aquasalis in UV light trap with CO2. We consider the UV light trap with CO2 to be the most reliable substitute for human bait catches.