Although Leminorella spp., members of the family Enterobacteriaceae, were previously isolated from feces and urine specimens, clinical correlates have not been studied. We conducted a retrospective study to investigate the clinical significance and disease spectrum of these organisms, as well as their antibiotic susceptibility patterns. Identification and susceptibility testing were performed by an automated system. Eighteen cases were identified retrospectively during a 28-month period (1/97 to 4/99), representing an incidence of 11 cases per 100,000 patient admissions. The medical records of 14 patients were reviewed. The average patient age was 67 years, and 78% were males. Patients had multiple and diverse underlying conditions which might have predisposed them to infection. Leminorella spp. were classified as definite pathogens in 43% of the cases, probable pathogens in 29%, and possible pathogens in 21%. In one case of asymptomatic bacteriuria, the isolate had no clinical significance. All infections but one were nosocomial. Clinical syndromes included urinary tract infection in six patients, surgical site infection in three patients, and primary bacteremia, peritonitis, respiratory tract infection, and soft tissue infection in one patient each. Isolates were uniformly susceptible to imipenem. Other beta-lactam agents had poor activity against the isolates. We conclude that Leminorella spp. are significant nosocomial pathogens that are capable of causing a variety of clinical syndromes and are resistant to multiple antibiotic agents.