Atopic dermatitis (AD), a skin disease characterized by pruritus and chronic inflammation, results from a complex interplay between environmental and genetic factors. Thymic stromal lymphopoietin (TSLP), an IL-7-like cytokine, is believed to propagate AD lesions through T helper 2 (Th2) polarization. This paper describes the immunologic mechanisms involving TSLP in the generation of allergic disease. Specifically in AD, TSLP has been shown to be an inducer of myeloid dendritic cells, Th2 responses, mast cells, and natural killer T cells, thereby leading to cytokine secretion and the development of AD. We hope that further understanding of the TSLP pathway and its role in the pathogenesis of AD will lead to improved clinical management of AD in the future.