<i>Background:</i> Specific immunotherapy with allergen is the only causative treatment for IgE-mediated allergies such as stinging insect allergy or hay fever and works by the induction of blocking antibodies and regulatory T lymphocytes. <i>Objective:</i> Does a hypothetical obstruction of tumor surveillance presupposing the induction of regulatory T cells really justify detaining immunotherapy to oncologic patients as suggested by recent guidelines? <i>Methods:</i> We report 6 patients (4 female, 2 male) suffering or having suffered from stage 1 cancer (4 melanomas, 1 lung cancer, 1 breast cancer) and concomitant IgE-mediated allergy. Four of them had a history of severe anaphylactic reactions to the insect yellow jacket, the 5th suffered from allergic rhinoconjunctivitis to dust mites, and the 6th to grass/rye pollen. <i>Results:</i> Between 2004 and 2010, subcutaneous immunotherapy was safely performed in 5 patients without signs of tumor reactivation. The cancer in 2 of them was diagnosed immediately after specific immunotherapy had been initiated and in another 2 the active cancer phase had already finished years before; the 5th suffered from a relapse around the time of the initiation of immunotherapy. At the time of the writing of the manuscript, 4 of them had already concluded 3 years of treatment, another one almost 1 year. The melanoma in the 6th patient was diagnosed 5 months after reaching the maintenance dose. Immunotherapy with grass/rye pollen was aborted in this patient based on current guidelines. <i>Conclusions:</i> Specific immunotherapy was safely administered in patients suffering concomitantly from IgE-mediated allergy and lower stage cancer.