This chapter covers the organisms which belong to a group of taxonomically and phylogenetically diverse, Gram‐negative, non‐fermentative rods and coccobacilli. Most of the organisms are found in the environment, that is, soil and water. For each group of closely related species, the chapter presents their taxonomic history, addresses the clinical importance of the species, and describes the phenotypic data that are useful to differentiate this group from other groups and to differentiate the species within this group. It discusses antibiotic susceptibility characteristics and treatment options. Decisions regarding the significance of GNF in a clinical specimen must consider the clinical condition of the patient and the source of the specimen submitted for culture. Identification of GNF may be important to document health care‐related outbreaks linked to hospital environments or medical devices.