The genus Corynebacterium comprises aerobic, nonsporing, gram-positive rods. These organisms are common saprophytic inhabitants of the skin/mucous membranes, infrequently causing serious infections in humans (1). Systemic infection can occur, especially in patients with malignancy, immunosuppression, damaged heart valves, as a result of broad-spectrum antibiotic therapy, or break in skin/mucous membranes (1-3). Endocarditis, septicemia, osteomyelitis, meningitis, pneumonia, and soft tissue infections have been reported in such patients (1-3). The precise role of corynebacteria in the pathogenesis of urinary tract infection is unknown. This paper describes a case of pyelonephritis and septicemia due to a diphtheroid-like organism similar to Corynebacterium group E.