Non-operative management of splenic trauma is now well established; however, the role of conservative management in spontaneous splenic rupture is undetermined. The leading cause of spontaneous splenic rupture is infectious mononucleosis. We report on the management of four patients with spontaneous rupture, in association with infectious mononucleosis. Three patients eventually required splenectomy, and one was successfully managed non-operatively. The comparative risks of operative and non-operative management are discussed. We believe that when splenic rupture complicates infectious mononucleosis, early splenectomy is the most appropriate management.