The present publication describes the actual situation anno 2005 with respect to registration of allergen products for specific immunotherapy (SIT) in Europe. It is concluded that the lack of the implementation of regulations and directives in force, is due to underestimation of the specific demands and aspects of the pathogenicity of allergic diseases at the one hand and of allergen products as a unique set of biological medicinal products at the other. The issues of regulatory nature that need careful attention and consideration in the opinion of the manufacturers are given in a number of statements. The main conclusion is that an EU-guideline for allergen products is urgently needed. A dialogue between regulatory authorities and representatives of the manufacturers, prior to the formulation of a new guideline seems of the utmost importance, as to prevent a similar stalemate as after the introduction of the foreseen regulatory measures of the past. The new guideline should include: An allergen product monograph. Recommendations for clinical development of allergen products like: Number of patients for efficacy and safety Acceptability of different efficacy parameters. Recommendations for toxicology.