We investigated the dispersal distance of the onion thrips, Thrips tabaci Lindeman, using traps. In a greenhouse, fourteen hours after releasing thrips, we found insects at sticky traps up to 54 m from the release point. The estimated mean dispersal distance (±SE) was 7.4±0.25 m at thirty-nine hours after releasing thrips. In a field, forty-eight hours after releasing thrips applied with the fluorescent brightening agent, we found insects at traps up to 119 m from the release point. The estimated mean dispersal distance (±SE) was 66.6±10.7 m.