This report describes a rare case of a patient with splenic tuberculosis (TB) who developed spontaneous splenic rupture after 10 weeks of antituberculous chemotherapy. The patient responded well to the antituberculous regimen prior to the spontaneous splenic rupture. We considered a paradoxical reaction as a cause of the splenic rupture. The patient underwent splenectomy and continuously received initial antituberculous drugs without change. To the best of our knowledge, this is the first report of spontaneous splenic rupture as a paradoxical reaction to antituberculous chemotherapy in an immunocompetent host with splenic TB.