The purpose of this review is to examine in detail the new advances in the pathomechanisms and diagnosis of immediate and nonimmediate hypersensitivity reactions to quinolones, as well as analyze cross-reactivity among different quinolones.Hypersensitivity reactions to quinolones, especially anaphylactic reactions, have become more common in the past decade. This phenomenon could be related to their increased consumption. Although attempts have been made to standardize skin testing, the diagnosis of immediate hypersensitivity reactions to quinolones is mainly based on drug provocation. Some in-vitro, radioimmunoassay and basophil activation tests have also been used for diagnostic purposes, with results indicating that they could be complementary to in-vivo tests. Cross-reactivity seems to exist between first and second-generation quinolones, with lower levels with the third and fourth generations. However, no general rules exist for predicting cross-reactivity and it needs to be analyzed patient by patient. Nonimmediate hypersensitivity reactions also exist, especially maculopapular exanthema and fixed drug eruptions, and a T-cell mechanism has been demonstrated.Over the past decade the number of hypersensitivity reactions to quinolones has increased. These reactions can be severe and diagnosis difficult to confirm. Although new in-vitro tests hold promise, drug provocation testing remains the most frequently used and reliable diagnostic method.