Spray nozzles are important in metering the liquid, atomizing, and controlling the distribution of spray over the spray swath. The effects of nozzle wear on flow rates, spray patterns, and droplet size spectrums delivered by fan pattern nozzles made from different materials were investigated. The relative wear rates of nozzle materials varied greatly with different times of use. At the end of test periods, hardened stainless steel was the most resistant to wear, followed in order of decreasing resistance to wear by stainless steel, plastic, nylon and brass. Nozzles with lower capacities wore at faster rates than nozzles with higher capacities. An automated computerized weighing system was developed to rapidly evaluate the effect of nozzle orifice wear on the spray deposit distribution. The results indicate that there was little difference between the spray deposit distributions of new and worn fan nozzles. The width of the spray pattern remained nearly constant but the worn nozzles delivered greater volumes of liquid in the centers of the patterns. Generally there was little difference in droplet size distributions between new and worn nozzles.