Atopic dermatitis (AD) is a common skin disorder. Although a wide range of therapeutic regimens are available, they have some limitations, including high medical costs. However, evidence suggests that adjuvant regimens such as water bathing are inexpensive and effective approaches for the management of AD. Bathing with either tap water or seawater alone can improve AD symptoms and signs. Combination of water bathing with topic emollient or corticosteroids can synergically alleviate AD. The underlying mechanisms by which water bathing benefits AD include improvements in epidermal function, inhibition of mast cell and Langerhans cell function, reductions in serine protease expression and activity, inhibition of cytokine expression, and upregulation of expression levels of antioxidant enzymes, as well as antimicrobial peptides. In this review, we summarize the effects of water bathing on AD in both humans and murine models as well as the underlying mechanisms.