On 9 December 2006 birders visiting a small farm pond near Palo Verde, Maricopa County discovered a peculiar immature gull among Ring-billed Gulls. As the photos illustrate, the combination of small size, distinctive structure, and specific plumage patterns seem to be enough to establish it as a Lesser Black-backed Gull. If accepted, this record will provide Arizona’s first for this long overdue species.