Wing-flashing in northern mockingbirds (Mimus polyglottos) has been studied frequently, but its function remains unclear. I studied wing-flashing associated with northern mockingbird foraging during March–April 1998 in Alabama. Rate of prey attack was negatively related to wing-flashing rate, and wing-flashing rate was not significantly related to ambient temperature. Wing flashing was more likely during mid-day than during morning or evening periods, but was independent of cloud cover, lighting conditions (shaded versus open), and substrate type. Use of wing-flashing to simply flush or illuminate prey appeared unlikely. Wing-flashing may improve foraging efficiency by allowing northern mockingbirds to assess prey mobility or defensive ability.