Introduction: Claudins, tight junction proteins, are essential for maintaining an epithelial barrier function. We previously screened claudin subtypes in the human airway epithelial cell line and reported that claudin-3 (Cldn-3) was one of the main subtypes in the airway. Airway epithelial barrier dysfunction is known in patients with asthma. However, the role of Clnd-3 in asthma pathogenesis is not clear. Aim: To investigate the effects of Cldn-3 on allergic airway inflammation using Cldn-3-knockout (KO) mice. Methods: Cldn-3-KO mice were sensitized and exposed to ovalbumin (OVA) for the inhalation challenge. Airway pressure and differential cell counts in bronchoalveolar lavage fluid (BALF) were determined. The levels of interleukin (IL)-5 and IL-13 in BALF, and OVA-specific IgE in serum were measured by ELISA. The fluorescence-conjugated OVA uptake by pulmonary dendritic cells (DCs) and bone marrow-derived dendritic cells (BMDCs) was measured by flow cytometry. Results: The airway pressure of OVA-treated mice compared to saline-treated mice was elevated in Cldn-3-wild type (WT) mice but not in Cldn-3-KO mice. Eosinophil counts, IL-5, and IL-13 were lower in OVA-treated Cldn-3-KO mice than in OVA-treated Cldn-3-WT mice. OVA-specific IgE after OVA inhalation challenge in Cldn-3-KO mice was lower than in Cldn-3-WT mice but not before OVA inhalation challenge. The in vivo OVA uptake by pulmonary DCs in Cldn-3-KO mice decreased compared to Cldn-3-WT mice, while OVA uptake by BMDCs from Cldn-3-KO mice was similar to Cldn-3-WT mice. Conclusions: Cldn-3 deficiency may attenuate the eosinophilic allergic reaction decreasing inhaled antigen uptake by DCs in the lung.