Adverse reactions due to application of local anesthetics (LA) are quite often an indication to allergological examination. These reactions are much more farmacological, toxic or vasovagal nature, than really allergic, mediated by immunological mechanisms. Allergy to LA constitutes just 1% of all adverse reactions associated with an application of LA and fears concerning their heavy progress are not supported. Skin tests, i.e. skin prick tests as well as intradermal tests have very low specificity and sensitivity and their negativity is not a guaranty of subsequent tolerance of tested medicament. Therefore the correct diagnosis can only be established by incremental subcutaneous reintroduction of LA during carefully conducted and monitored challenge test. Such test is safe and usually well tolerated.