A 60-year-old man underwent retroperitoneal laparoscopic nephrectomy for left renal tumor (cT1bN0M0).The histopathological examination revealed Kidney cancer grade 3 pT1b. The following evaluations revealed multiple bone metastasis. The IFN-gamma with radiation therapy were performed. However the disease was progressive. So IL-2 70 million units per day 5 times a week started. The patient started to complain lower abdominal pain and watery diarrhea from administration day 28th. Blood test showed eosinophilia. At this point side effect of IL-2 therapy was suspected, then IL-2 was discontinued. But abdominal symptoms had continued. Consulting with a digestive physician, he diagnose as drug-induced colitis like ulcerative colitis by colon endoscopy. The symptoms were gradually improved by an antiallergic agent on our assumption that eosinophilia was concerned in this colitis. Many articles have reported that IL-2 was associated with the clinical mechanism of ulcerative colitis, but there seems no reports about such complications before. This case could suggest IL-2 relates to ulcerative colitis.