A study to evaluate the use of light-emitting diodes (LEDs) as an attractant for phlebotomine sand flies at two animal pens in a livestock area in Brazil was performed. Light-suction traps were operated overnight with the following light sources: green, blue, and incandescent (control) lights. In total, 22 individual collections were made at each site and 44 with each trap type. In total, 2,542 specimens belonging to 14 phlebotomine species were collected. The most abundant species in the light traps were Nyssomyia whitmani, Evandromyia evandroi, Micropygomyia goiana, Lutzomyia longipalpis, and Bichromomyia flaviscutellata. Taking the two sites together, the green-LED light was the most attractive, followed by the blue and incandescent lights, and the difference between the green-LED and the control was statistically significant. Most species were green-biased at both sites, but some species-specific differences were observed. However, even with these differences, the standard incandescent light was outcompeted by LEDs. The green-LED-biased response observed in the present study, together with numerous advantages in favor of LEDs, suggests that the green-LED light source can be used as an effective substitute for the currently used incandescent bulb in monitoring traps for phlebotomine sand flies in Brazil.