Anaphylaxis is a serious and probably lethal systemic reaction which occurs instantaneously after exposure to an allergen. It can occur after exposure to various triggers including allergic and non-allergic factors. When a trigger cannot be determined, idiopathic anaphylaxis is considered. In idiopathic anaphylaxis presenting with frequent attacks, long-term prophylaxis with H1 antihistamine and steroid treatment are recommended. Omalizumab, a humanized monoclonal antibody drug which decreases free immunoglobulin E molecules in the circulation, is approved for the treatment of chronic severe persistent allergic asthma. We report a 46-year-old female patient with severe uncontrolled allergic asthma and idiopathic anaphylaxis presenting with attacks of abdominal pain, generalized urticaria, feeling of strangulation in her throat and unconsciousness. Omalizumab at a dose of 375 mg once every 2 weeks was administrated and at the end of 3 months anaphylactic attacks had ceased. At the end of the sixth month of omalizumab therapy, her injection intervals were extended to 4 weeks. After she began experiencing moderate attacks of urticaria and hoarsening, however, initial treatment plan was reestablished. Currently, she has completed her first year of treatment without further attacks.