Quinolones are broad-spectrum antibiotics used for the treatment of several infectious diseases. Although they are frequently used due to high bioavailability and good safety, they may have psychiatric and neurological side effects such as depression, delirium, psychosis and convulsions. There have been published reports of delirium related with ciproşoxacin, gatişoxacin, yet according to our knowledge, there is no report implicating moxişoxacin as a contributor to psychosis. We present a 60 years old female patient, who was admitted to hospital with high fever, cough and fatigue. Moxişoxacin treatment was started with the diagnosis of atypical pneumonia. Disorganised speech, disturbances in perception and thought occurred on moxişoxacin treatment and resolved 3 days after withdrawal of moxişoxacin.