Adequate patient tolerance is essential for successful completion of safe endoscopic examination. Although there are many reported methods to increase patient tolerance, none of these fully resolve this problem. The aim of this study was to investigate whether relaxing the nasal airways increase patient tolerance to upper gastrointestinal endoscopy (UGE). A total of 300 patients scheduled for diagnostic UGE were randomized into three separate groups. Prior to the UGE procedure the first group was administered intranasal cortisone spray following nasal cleansing (INC). Patients in the second group were administered intranasal saline after nasal cleansing (INSP). The patients in the third group were treated with the standard endoscopic procedure alone (SEP). After the UGE procedure, both endoscopists and patients were asked to evaluate the ease of performing the procedure. Furthermore, patients who had undergone endoscopy before were asked to compare their current experience to their most recent endoscopy. Results shown that INC and INSP groups had significantly better tolerance than the SEP group. When comparing their current experience with the previous one, INC and INSP groups reported that the current experience was better. Conclusions: Taking measures to relax the nasal airways makes breathing more comfortable and increase patient tolerance during UGE.