Allergic diseases have a substantial epidemiological impact on pediatric population. Small molecule-based medicines have been traditionally used to manage the diseases. Omalizumab is the first monoclonal antibody-based medicine used in children’s allergy and shows great promises. It binds to free IgE and prevents it from binding to IgE receptor, thus interrupting the IgE-dependent allergic inflammatory cascade. Vast amounts of data demonstrates its effectiveness and well tolerance by patients, including the children. However, the drug was only approved to use in allergic asthma and chronic spontaneous urticaria (CSU), though other applications were explored in clinical trials. In this review, we summarized current pediatric applications of Omalizumab in allergic diseases, focusing on its usages beyond asthma and CSU, including allergic rhinitis, allergic bronchopulmonary aspergillosis, vernal keratoconjunctivitis, food allergy, and atopic dermatitis. In addition, we highlighted the unmet need and controversial issues of anti-IgE therapy.