Traumatic rupture of the spleen during the performance of a colonoscopy is a very rare complication. The more common complications after such procedures, diagnostic or therapeutic, include bleeding from and perforation of the bowel at the resected or biopsy site. However, the rate of these complications merely reaches one percent. In this case report the authors present and discuss the condition of a patient who underwent an urgent operation due to rupture of the spleen during a colonoscopy.