Matrix metalloproteinases (MMPs) recently appeared as key regulators of inflammation, allowing recruitment and clearance of inflammatory cells and modifying the biological activity of many peptidic mediators by cleavage. MMP-19 is a newly described MMP and preferentially cleaves matrix proteins such as collagens and tenascin-C. The role of MMP-19 in asthma has not been described to date. The purpose of the present study was to assess MMP-19 expression in a murine asthma model and to address biological effects of MMP-19 deficiency in mice. Allergen-exposed wild-type (WT) mice displayed an increased expression of MMP-19 mRNA and an increased number of MMP-19-positive cells in the lungs detected by immunohistochemistry. After allergen challenge of MMP-19 knockout (MMP-19-/-) mice, an exacerbated eosinophilic inflammation was detected in bronchoalveolar lavage fluid and bronchial tissue along with an increased airway responsiveness to methacholine. A shift towards increased Th2-driven inflammation in MMP-19-/- mice was demonstrated by 1) increased numbers of cells expressing the IL-33 receptor T1/ST2 in lung parenchyma, 2) increased IgG1 levels in serum and 3) higher levels of IL-13 and CCL11 in lung extracts. Tenascin-C was found accumulated in peribronchial areas of MMP-19-/- after allergen challenges as assessed by Western blot and immunohistochemistry analysis. We conclude that MMP-19 is a new mediator in asthma, preventing tenascin-C accumulation and directly or indirectly controlling Th2-driven airway eosinophilia and airway hyperreactivity . Our data suggest that MMP-19 might act on Th2 inflammation homeostasis through preventing tenascin protein accumulation.