The resting behavior ofAedes aegypti(L.) adults was investigated in 14 districts of Panama City, Panama, in relation to ground ultra-low volume (ULV) applications of malathion. Adults primarily rested inside the premises (75.1%) at a distance >6 m from the street (86.4%). Both sexes rested mainly in bedrooms, living rooms, and bathrooms. The small ULV aerosol droplets (2–4 μm) penetrated all indoor resting sites ofAe. aegypti,but in low amounts. Because of the low amount of insecticide reaching the primary resting sites within the premises, limited control of theAe. aegyptiwas obtained. This limited the potential effectiveness of ground vehicle ULV applied insecticide as a dengue epidemic control method.