Fluoroquinolones occupy one of the leading places when using worldwide. However, the range of adverse reactions at post-marketing levels is expanding, that requires attention and restrictions. The specified list of adverse reactions in the instructions for the drugs is supplemented by a great attention to disorders of the nervous system, joints and the risk of rupture of aortic aneurysm. Additional indications comprise: elderly patients, previous history of reactions to fluoroquinolones, renal or joint dysfunction, interaction with glucocorticoids. These limitations must be taken into account by physicians in daily practice.