The control of medically important arthropod vectors of human and animal disease is a high priority for both public health and military officials. Because droplet size of pesticide spray material is a critical factor affecting vector control applications, the droplet-size spectra produced by 11 sprayers and 3 spray formulations were evaluated. Droplet-size spectra were measured by a laser diffraction instrument, a hot-wire system, and rotating slides. There were considerable differences in the droplet-size spectra produced by the different sprayers tested. The volume median diameter (D_V0.5) for the water-based sprays ranged from 4.7 to 211 µm, depending on the sprayer, and the percent of spray volume contained in droplets less than 20 µm (%vol <20 µm) ranged between 0.5% and 98.9%. The D_V0.5 measurements for the oil-based sprays ranged from 9.4 to 125.3 µm and the %vol <20 µm ranged between 2.4% and 97.9%. The correlations between the D_V0.5 measured by the laser system (D_V0.5-laser) and the mass median diameter, Sauter diameter, and D_V0.5 measured by the AIMS probe were all significant. Generally, the slide D_V0.5s were numerically similar to the D_V0.5 from the laser system and the Sauter diameter from the Army Insecticide Measuring System probe. There was less consistent agreement between the % <32 µm values obtained from the slides and those from the other 2 samplers. The information presented can be used by applicators to select the sprayer that produces the droplet-size spectra needed for their particular application situation.