Nasal provocation tests with suspension of oral contraceptive drugs (OCD) as well as of their components (Estrogen, Progestin, Non-hormonal components) were performed in two groups of women, mostly suffering from perennial rhinitis or pollinosis, and all taking oral contraceptive drugs. Thirteen of the 15 patients from the first experimental group, in whom the increase of the nasal complaints was anamnestically related to the oral contraception, and three of the 34 patients from the second experimental group (without anamnestical relation to the oral contraception) demonstrated a positive nasal mucosa response after topical challenge with OCD. All OCD positively reacting patients showed also a positive nasal mucosa response after challenge with the Estrogen and one patient also after Progestin challenge. Non-hormonal components did not cause any reaction. This nasal mucosa response was interpreted as a possible allergic reaction. Type I (immedicate hypersensitivity of the nasal mucosa due to Estrogen in blood contraceptives. This response begins within 10 minutes, reaches its maximum within 30 minutes, and does not disappear completely within 60 minutes in most patients. None of the patients from control groups (atopy--without OCD; OCD takers--without atopy; male volunteers without atopy) demonstrated any positive nasal mucosa response to OCD or their components.