Introduced plants and animals have been a prominent worldwide environmental issue for decades; however, considerable debate and confusion remain over how to list and otherwise categorize these species. This paper describes a process for categorizing exotic freshwater fishes that have been found in public waters. The basis of this process has been used by the Florida Fish and Wildlife Conservation Commission for nearly 30 years. Reproducing exotic fishes are grouped into three subcategories (established, possibly established, and localized) using species-specific biological and population characteristics resulting in a list that is helpful for prioritizing research and management activities. The purpose of this paper is to stimulate interest in standardizing processes for categorizing introduced species based on how well they adapt to new environments.