Abstract Introduction: High-volume corticosteroid nasal irrigation is a treatment option in patients with chronic rhinosinusitis. In Brazil, alternatives are used to optimize its cost and popularize its use, such as 1% compounded budesonide drops or betamethasone cream, and it is necessary to study these treatment modalities. Objective: To evaluate the clinical response of nasal irrigation with 1% compounded budesonide drops or betamethasone cream compared to nasal sprays utilized in patients with chronic rhinosinusitis. Methods: This was a retrospective observational study with 257 patients. One hundred and eight patients using corticosteroid nasal irrigation (292 treatment cycles) and 149 using corticosteroid nasal spray (300 treatment cycles) were included. Evaluation of subjective improvement, adverse events, exacerbations, and objective assessments with SNOT-22 and Lund-Kennedy endoscopic score were performed, in addition to sub-analyses related to nasal polyps and previous surgery. Results: Corticosteroid nasal irrigation and corticosteroid nasal spray improved the Lund–Kennedy endoscopic score, with more adverse events in the corticosteroid nasal irrigation group. Previous surgery increased corticosteroid nasal irrigation improvement, with greater subjective improvement and fewer exacerbations. 1% compounded budesonide drops were better than betamethasone cream in the Lund-Kennedy endoscopic score, with fewer adverse events. A 1,000 μg dose of 1% compounded budesonide drops was more effective than 500 μg. Conclusion: Corticosteroid nasal irrigation was effective in improving the Lund-Kennedy endoscopic score in chronic rhinosinusitis, especially in patients with nasal polyps and previous surgery, in addition to promoting a higher rate of subjective improvement and fewer exacerbations than corticosteroid nasal spray, but with more adverse events. 1% compounded budesonide drops improved the Lund-Kennedy endoscopic score with fewer adverse events than betamethasone cream, particularly at higher doses (1000 μg).