Data obtained from 1996 to 2002 on 13 patients with Rhizobium radiobacter infections were analyzed. Ten patients (76%) had underlying hematological malignancy or solid-organ cancer. Six patients (46%) had febrile neutropenia during the course of R. radiobacter infection. The majority (54%) of infections were catheter-related bacteremia, and 92% of infections were hospital acquired. All the patients survived. Eighteen isolates were recovered from the 13 patients, and each isolate was susceptible to cefepime, piperacillin-tazobactam, carbapenems, and ciprofloxacin. The pulsed-field gel electrophoresis profiles differed among the isolates recovered from different patients, indicating the absence of nosocomial spread of the organism.