Objectives To evaluate the CT features of ruptured GISTs and factors that might be predictive of rupture through comparison with CTs taken prior to rupture and CTs of non-ruptured GIST. Methods Forty-nine patients with ruptured GIST and fortynine patients with non-ruptured GIST matched by age, gender and location were included. Clinical data including pharmacotherapy were reviewed. The imaging features were analyzed. Prior CT obtained before rupture were evaluated. Results The most common location of ruptured GIST was small bowel with mean size of 12.1 cm. Ruptured GIST commonly showed wall defects, >40 % eccentric necrosis, lobulated shaped, air density in mass, pneumoperitoneum, peritonitis, hemoperitoneum and ascites (p < 0.001-0.030). Twenty-seven of 30 patients with follow up imaging received targeted therapy. During follow-up, thickness of the tumour wall decreased. Increase in size and progression of necrosis were common during targeted therapy (p = 0.017). Newly developed ascites, peritonitis and hemoperitoneum was more common (p40 % eccentric necrosis, wall defects and lobulated shape. The progression of necrosis with increase in size and decreased wall thickness during targeted therapy may increase the risk of rupture. Rupture should be considered when newly developed peritonitis, hemoperitoneum, or ascites are noted during the follow-up.