Background Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have severe health problems require systemic steroids and multiple sinus surgery, Dupilumab is a new biological treatment of type 2 inflammation by its effect on interleukin 4 and interleukin 13 which used in atopic dermatitis and bronchial asthma. Aim of the work is to investigate the effect of High irrigation nasal steroids versus intranasal steroids in chronic sinusitis with polypi under treatment of dupilumab. Patients and Methods: This study included 70 patients under treatment of dupilumab 300 mg in the form of injection every 2 weeks for 24 weeks, the patients divided into GI n=35 who receive high irrigation nasal steroid and GII n=35 who receives nasal steroids for 24 weeks, this study assess the management Plan for chronic sinusitis with nasal polypi as regards nasal congestion, smell score, nasal endoscopy score, CT score (Lund Mackay). Results: This study found that both techniques improve nasal congestion score which is significant p