The patient was a 74-year-old woman who was diagnosed with advanced breast cancer, T4aN0M0, stage IV. She was placed on chemotherapy of weekly paclitaxel (PTX) (60 mg/m(2) day 1, 8, 15 with 1 course consisting of 28 days). We used dexamethasone (8 mg/body) as premedication for chemotherapy every time. Three courses were performed with no severe adverse reaction. On the fourth course, day 8, she complained of nausea, vomiting, paroxysmal cough and fecal incontinence after a few minutes of dexamethasone administration. Her blood pressure dropped to a minimum of 64 mmHg (systolic pressure) and she soon became drowsy. We diagnosed the anaphylaxis-like reaction for dexamethasone, immediately discontinued dexamethasone infusion, and treated her successfully. Forty minutes after the episode had occurred, she recovered. The few reports on anaphylaxis or anaphylaxis-like reaction to dexamethasone must be taken into account when we use these drugs.