We report a case of strangulation of the penis with a rubber band. A 68-year-old man visited our hospital for treatment of a markedly swollen penis. Physical examination revealed one rubber band tightly coiled around the penis. The rubeer band was soon removed, gangrene of the penis continued. A high fever, chills and hypotension were recognized. Sepsis was presumed, and administration of antibiotics was started. Microbiologic cultures revealed streptococcus agalactiae in blood. Since his general condition did not improve, we performed partial penectomy. After the surgery, he showed complete recovery.