Introduction: Music interventions have been recognized as a method to reduce pain during medical procedures, but within medical imaging the subject has received little attention. Endorectal ultrasonography examination is in some patients associated with anxiety and pain, and since in Denmark pain relief is usually not administered by the Department of Radiology, it is important to find effective alternative methods to help patients manage their pain during imaging procedures. The primary aim of this study was to evaluate the effect of music on self-reported pain during endorectal examination of rectal cancer patients. Methods: A prospective questionnaire study of patients undergoing endorectal ultrasonography was conducted. Patients were randomized into two groups: a music group (n = 66), and non-music group (n = 60). Standard endorectal ultrasonography was performed in all patients. Pain was self-assessed using a Visual Analogue Scale ranging from 0 to 10, with 0 representing “no pain” and 10 maximum pain. Results: A total of 126 patients were included in the study, 81 (64.3%) men and 45 (35.7%) women. The demographics were similar in the two groups. The mean pain score during endorectal ultrasonography in the music and non-music group was 1.95 and 2.30, (p = 0.404). Conclusion: In this randomized study music did not significantly affect the pain level experienced by the patients. Endorectal ultrasound was not entirely painless but less painful than colonoscopy (Visual Analogue Scale 2.1 and 3.8, respectively). Implications for practice: Health care professionals may consider using music during painful procedures.