Several aspects concerning collection and analysis of ULV droplets were clarified and defined. Experimental comparison of 5 ULV droplet collection methods indicated that small settling chambers and mechanical slide rotators with Teflon coated slides are best suited for field collection of droplets from ULV generators. Decrease in diameter due to evaporation for 1 to 10 um malathion droplets was insignificant (3.26%) when droplet diameters were determined within 24 hr of treatment, and the volume decrease was more significant (7.68%) at 24 hr. Due to lower droplet velocities and environmental effects, collections of malathion droplets 7.6 m from the nozzle, as indicated by label procedures, may not be as representative of the actual droplet spectrum as the same method used at 1.2 m.