Recent advances in the knowledge of asthma pathobiology suggest that biological therapies that target cytokines can be potentially useful for the treatment of this complex and heterogeneous airway disease. The use of biologics in asthma has been established with the approval of the humanized monoclonal immunoglobulin E-targeted antibody omalizumab (Xolair; Genentech/Novartis) as an add-on treatment for inadequately controlled disease. Furthermore, evidence is accumulating in support of the efficacy of other biologics, such as interleukin-5 (IL-5)- and IL-13-specific drugs. Therefore, these new developments are changing the scenario of asthma therapies, especially with regard to more severe disease. The variability among patients' individual therapeutic responses highlights that it will be necessary to characterize the different asthma subtypes so that phenotype-targeted treatments based on the use of biologics can be implemented.