Both white ginseng (WG, dried root of sp.) and red ginseng (RG, steamed and dried root of sp.) are reported to exhibit a variety of pharmacological effects such as anticancer, antidiabetic, and neuroprotective activities. These ginsengs contain hydrophilic sugar-conjugated ginsenosides and polysaccharides as the bioactive constituents. When taken orally, their hydrophilic constituents are metabolized into hydrophobic ginsenosides compound K, Rh1, and Rh2 that are absorbable into the blood. These metabolites exhibit the pharmacological effects more strongly than hydrophilic parental constituents. To enforce these metabolites, fermented WG and RG are developed. Moreover, natural products including ginseng are frequently used for the treatment of allergic disorders. Therefore, this review introduces the current knowledge related to the effectiveness of ginseng on allergic disorders including asthma, allergic rhinitis, atopic dermatitis, and pruritus. We discuss how ginseng, its constituents, and its metabolites regulate allergy-related immune responses. We also describe how ginseng controls allergic disorders.