Surgery, anticoagulation therapy, pregnancy, and hormone treatments, such as bromocriptine, are well-characterized precipitating factors for pituitary apoplexy. However, whether cytotoxic chemotherapy for systemic cancer could cause pituitary apoplexy has not been investigated. Here, we present a case of a 41-year-old woman who developed a severe headache with decreased visual acuity after intravenous cytotoxic chemotherapy to treat metastatic breast cancer. Preoperative neuroimaging revealed pituitary adenoma with necrosis. Operative findings and pathologic examination concluded extensive necrosis with a small intratumoral hemorrhage in a pre-existing pituitary adenoma. We reviewed two additional previously published cases of pituitary apoplexy after systemic chemotherapy and suggest that cytotoxic chemotherapy may induce pituitary apoplexy.