Cushing’s syndrome is characterized by excessive cortisol and immuno-suppression. We experienced a case of Cushing’s syndrome caused by adrenocortical carcinoma that was complicated by multiple opportunistic infections. A 37-year-old woman with adrenocortical carcinoma (ACC) presented with decreased mental ability and high fever one week after undergoing chemotherapy. Her initial blood culture revealed methicillin-resistant bacteremia accompanied by septic pneumonia. We admitted her to the intensive care unit and treated her for invasive pulmonary aspergillosis (IPA), pneumonia (PJP), candidemia, and pneumonia with broad-spectrum antibiotics and antifungal agents. Nevertheless, her clinical course worsened and she died. Herein, we report a case of Cushing’s syndrome associated with cortisol-secreting ACC that presented with multiple opportunistic infections, including MRSA bacteremia, septic pneumonia, candidemia, PJP, and IPA, illuminating a relationship between hypercortisolemia and opportunistic infections.Copyright © 2020 by The Korean Society of Infectious Diseases, Korean Society for Antimicrobial Therapy, and The Korean Society for AIDS.