Colonic leiomyoma is a rare condition. Smooth muscle tumours arising from the colon constitute only 3% of gastrointestinal leiomyomas. Complete endoscopic removal of the tumour is a problem because it is often submucosal in origin. We report a patient with a 5 mm leiomyoma of the colon that was successfully removed by conventional colonoscopic snare electrocauterisation, without complications.