Analysis of bronchial hyperresponsiveness using bronchial provocation tests are a key feature in the diagnosis of asthma, as well as a valid tool for monitoring disease severity, clinical course, and treatment response. We review non-specific bronchial challenge tests, including pharmacological stimuli (methacholine, adenosine) and physical stimuli (exercise, hypertonic saline, cold air hyperventilation). Although there is some correlation among responses to the distinct tests, individual responses are also observed. The indication for a single test will depend on whether the procedure will be used for diagnostic or epidemiologic purposes, and on experience of its use. Frequently, complementary information will be obtained. Indirect airway challenges tests such as physical stimuli and adenosine are more specific for asthma diagnosis.