We present the first documented account of adult greater roadrunner (Geococcyx californianus) feeding on California least tern chicks (Sterna antillarum browni). This predation event occurred at a designated nesting site within Batiquitos Lagoon, San Diego County, California, in 1996. We hypothesize that the concentrated foraging efforts by the roadrunner were an opportunistic response to a localized abundance of favorable prey items, which warrants an increased awareness at other least tern nesting sites situated in close proximity to greater roadrunner habitat.