To control for acute infectious disease, identification of the causative agent and determining the antibiotic susceptibility of the pathogen are crucial. If a particular organism is rare and relevant etiological information is scarce, it becomes difficult to determine appropriate antibiotic and therapy duration. Enterococcus hirae is a pathogen that infects animals, but rarely causes human infections. We present two cases of E. hirae-related pyelonephritis with successful treatment. Herein, our experience is discussed with relevant literature review.