Background: Quince (Cydonia oblonga Miller) is a deciduous shrub belonging to the Rosaceae family. Quince seed extract has long been used as a cosmetic ingredient for its moisturizing effect. However, little is known about whether quince seed extract has therapeutic effects on keratinocyte-associated skin inflammation. Methods: In the present study, we investigated the effect of the topical application of ethanol extract of quince seeds (QSEtE) on atopic dermatitis (AD) symptoms in NC/Nga mice. The direct effect of QSEtE on keratinocytes was evaluated using the human keratinocyte cell line HaCaT. Results: The preliminary application of QSEtE markedly reduced house dust mite allergen-induced skin lesions. The expression of thymus-and activation-regulated chemokine (TARC) in dorsal skin was downregulated. QSEtE directly suppressed the expression and production of TARC in HaCaT cells. Conclusions: The results suggest that the topical application of QSEtE is effective in preventing the onset of and ameliorating the atopic symptoms of keratinocyte-associated skin inflammation by suppressing TARC production in keratinocytes.