An 83-year-old man was admitted for right lower lobe pneumonia which did not improve after a 5-day outpatient treatment with amoxicillin/clavulinate and clarithromycin. An empiric treatment with levofloxacin was started with a significant improvement after 24 h of this treatment. On the third day of hospitalization, delirium developed, while the patient was afebrile and with normal blood oxygenation. Treatment with levofloxacin was stopped, and a complete resolution of the patient's delirium was observed 2 days later. To the best of our knowledge, this is the third case of levofloxacin-induced delirium described in the medical literature.