This study aimed to determine the effect of Binaural Beats(BB)on feeling of pain, and patient comfort during colonoscopy without sedation. It is a randomized, controlled, double-blind procedural study of 115 patients that underwent colonoscopy without sedation. The patients were randomly assigned into the experimental group (n = 42) and the control group (n = 48) that were given BB starting 5 min before and continuing until the end of the colonoscopy procedure without any intervention other than routine nursing care. Measures of the state of anxiety (VAS-Anxiety scale) administered before the procedure, and measures of feeling of pain (Visual Analogue scale VAS-pain), Satisfactory and Willingness to repeat the procedure as Likert scales were also collected soon after the colonoscopy procedure. Feeling of pain was lower and scores of the level of comfort were higher in the experimental group when compared to the control group (p < 0.05). BB is an effective and safe method for reducing pain and improving patient comfort in cases undergoing colonoscopy without sedation. Since BB method is a non-pharmacological, non-invasive, inexpensive and simple method without any side effects, it may be used to reduce the feeling of pain and discomfort for non-sedated patients undergoing colonoscopy.