Background: Atopic dermatitis (AD) is a chronically relapsing skin disease that is associated with a disturbance of the epidermal barrier function. Changes in the human skin microbiome have been suggested as a risk factor for AD. Objective: The aim of this study was to explore the species distribution of microflora on the skin and in the oral cavity of healthy volunteers and patients with AD. Methods: Samples for culture were obtained from both lesional skin and the oral cavity in 211 patients with AD and from both the normal skin and oral cavity of 24 healthy controls. Species identification was performed with the VITEK 2 system (bioMerieux Inc., Hazelwood, MO, USA). Results: The isolation of Staphylococcus aureus from the skin was statistically more frequent among patients with AD than among healthy controls, while the isolation of Staphylococcus hominis and Micrococcus luteus were statistically more frequent among healthy controls than among patients with AD (p＜0.05). In the oral cavity, S. aureus and Candida albicans were found more frequently in patients with AD, but the difference did was not statistically significant. Conclusion: This study provides an important insight into the species distribution of microorganisms on human skin and in the oral cavity. Further investigation is required to determine the role of specific microorganisms in the etiology and pathogenicity of AD. (Korean J Dermatol 2016;54(1):1∼7)