Asthma is a chronic lung inflammatory disease affecting from 5 to 10% of the population. It generally appears with periods of crisis alternating with free periods, but inflammation is always present. Allergic asthma manifests with paroxysmal crisis of bronchospasm, hissing-like respiratory noises, dyspnea, and respiratory distress syndrome. Different studies have shown an increase of IgE serum levels in subjects suffering from allergic asthma. Xolair is a monoclonal antibody that binds the Cε3 domain of IgEs, inducing a conformational change of the immunoglobulin, a concealment of FcεRI and FcεRII receptors binding sites, thus precluding binding by IgEs and therefore stopping the release of inflammation mediators. Xolair is indicated as add-on therapy to improve asthma control in adult and adolescent patients (12 years of age and above) suffering from severe persistent allergic asthma. The aim of this review is 1) to explore the safety and tolerability of Xolair in asthma therapy and 2) to examine recent important developments focusing on treatment strategies of asthma with Xolair.