Objective Neutrophilic chronic rhinosinusitis with nasal polyps (CRSwNP) occurs predominantly in Eastern Asian subjects. Appropriate treatments for this endotype have not been elucidated. This study aimed to evaluate the effect of local glucocorticoid budesonide nasal spray on neutrophilic CRSwNP.Methods Fifteen CRSwNP subjects were enrolled and received budesonide treatment for three months. Nasal samples were obtained from normal nasal mucosa and nasal polyps (NP) of CRSwNP patients, and their endotypes were identified using immunofluorescent staining. Then the infiltration of neutrophils (Neu) was examined with immunohistochemical staining before and after budesonide treatment. After that, Hematoxylin-Eosin and Periodic Acid-Schiff stainings were used to assess goblet cells and submucosal gland cells before and after the therapy. Finally, the effects of the treatment on inflammatory mediators including myeloperoxidase (MPO), interferon-γ (IFN-γ) and mucin (MUC)5AC as well as MUC5B were evaluated through enzyme linked immunosorbent assay.Results All the recruited patients belonged to the neutrophilic endotype. The number of Neu was increased in NP compared to normal nasal mucosa, and was not decreased significantly after budesonide treatment. Goblet cell numbers and submucosal gland cells scores in NP were higher than those in the normal tissues, and were not reduced significantly after the treatment. The contents of MPO, IFN-γ, MUC5AC and MUC5B were enhanced compared to normal mucosa. However, the content differences of above substances in NP before and after treatment were statistically insignificant.Conclusion Budesonide can not treat neutrophilic NP effectively.