For most people Hymenoptera stings result in transient and bothersome local inflammatory responses characterized by pain, itching, redness and swelling. In contrast, for those presenting an IgE-mediated allergic reaction, a re-sting may cause life-threatening reactions. In such patients, correct diagnosis is an absolute prerequisite for effective management, i.e. venom-specific immunotherapy. Generally, identification of the offending insect involves a detailed history along with quantification of venom-specific IgE antibodies and venom skin tests. Unfortunately, due to uncertainties associated with both tests, correct diagnosis is not always straightforward. This review summarizes the potentials and limitations of the various in vitro tests that are currently being used in the diagnosis of Hymenoptera venom allergy. Particular attention is paid to the potential of novel cellular tests such as basophil activation tests and component-resolved diagnosis with recombinant venom allergens in the diagnostic approach of patients with difficult diagnosis, i.e. cases in whom traditional venom specific IgE and skin tests yield equivocal or negative results. Finally, this review also covers the recent discoveries in the field of proteome research of Hymenoptera venoms and the selection of cell types for recombinant allergens production.