Listeria monocytogenes is a self-limiting gastroenteritis agent in healthy adults, while it can also cause more severe conditions such as bacteremia and meningitis in pregnant women, newborns, elderly and immunosuppressed patients. In our report, an 81-year-old geriatric patient presented with fever, dysuria, and gastroenteritis. The patient was prescribed ceftriaxone empirically upon admission, and urine culture was reported as Escherichia coli sensitive to ceftriaxone. However, there were still no fever response and clinical improvement on the third day of antibiotic treatment. In blood culture obtained upon admission, Listeria monocytogenes was grown on the third day. The patient responded to treatment after her treatment was changed to ampicillinsulbactam. However, a pulmonary embolism developed on the 14th day of admission, and the patient was transferred to the intensive care unit. In our report, it was stated that attention should be paid to the nutrition of patients in elderly. We also emphasized that blood culture should be taken from every patient who represents with fever and the importance of early and appropriate treatment.