Abstract: A pharmaceutical preparation for the prophylactic treatment of allergies which contains as active ingredient an extract of pollen which contains nor more than 5% by weight, referred to the dry weight of the extract of pollen, of proteins having a high molecular weight or which is completely free of proteins of high molecular weight. The active ingredients of the inventive pharmaceutical preparation have themselves no allergen activity. To those human beings and children which in the years before suffered from severe symptoms of hay fever or asthma, the inventive pharmaceutical preparations were administered, preferably orally, during about three months before the allergy usually had occurred, for instance in the months February until April. By said administration the occurring of the pollen allergy in spring time and during the whole summer could be completely prevented.