Locked-in syndrome is a rare clinical syndrome due to basilary artery thrombosis generally associated with trauma, vascular, or cardiac malformation. It can present as various types of clinical evolution and occasionally masquerades as other pathological conditions, such as infective meningoencephalitis. These complications are the cause of diagnostic delay, if not promptly recognised, followed by patient death. We report the case of a 42-year-old female with a systemic B and cutaneous T-cell non-Hodgkin's lymphoma, with a severe neutropenia lasting over a year, who eventually developed a rapid and fatal fungal mucormycosis sepsis following a skin infection on her right arm, associated with locked-in syndrome and meningoencephalitis.