Background Mucociliary function is affected by temperature. Exposure to cold air may impair ciliary beat frequency. While saline nasal irrigation improves in ciliary beat activity, there is no evidence supporting the use of heated saline irrigation in treating patients with chronic rhinosinusitis. Objective To compare the effects of heated saline to room-temperature saline nasal irrigation on mucociliary clearance in chronic rhinosinusitis patients. Methods Adult patients with chronic rhinosinusitis were randomized into two groups receiving either heated saline or room-temperature saline nasal irrigation. Healthy subjects were included as control. Saccharin transit time was measured before and after nasal irrigation. Nasal patency was assessed by peak nasal inspiratory flow, anterior rhinomanometry, acoustic rhinometry, nasal obstruction score, and breathe-comfort score. Any adverse events were reported. Results Twenty-three patients with chronic rhinosinusitis and nine healthy subjects were enrolled. Saccharin transit time was decreased after nasal irrigation in both heated saline subgroup (baseline 12.3 ± 4.5 min vs. postirrigation 8.4 ± 4.9 min, p = 0.05) and room-temperature subgroup (baseline 12.8 ± 5.0 min vs. postirrigation 8.9 ± 4.2 min, p = 0.01). The saccharin transit time improvement was not different between heated saline (3.8 ± 6.2 min) and room-temperature saline (3.8 ± 4.0 min), p = 0.13. Postheated saline irrigation saccharin transit time of chronic rhinosinusitis patients (8.4 ± 4.9 min) was not different to healthy subjects (9.2 ± 3.7 min), p = 0.69. Nasal patency was not different between groups. There was no adverse event reported. Conclusion Nasal saline irrigation is beneficial to patients with chronic rhinosinusitis on mucociliary improvement. Warming saline is not necessary and adds no additional benefit to room-temperature saline irrigation.