Gastro-intestinal stromal tumors (GIST) represent a type of mesenchymal tumors, located in the digestive tract wall, with the possibility of alternate locations such as the caul or the mesentery. The relapse prognosis is closely corelated with the dimensions of the tumor, the rate at which tumor cells divide, the cellularity of the tumor and the nuclear pleomorphism. The definitive treatment for these types of tumors is surgical resection, associated with tyrosine- kinase inhibitors.The largest gastro-intestinal stromal tumor ever recorded in medical literature measured 42/31/23 cm and weighed in at 18.5 kg. The following case presentation is of a patient aged 65 at his first admission, who received tyrosine-kinase inhibitors of different generations, associated with multiple surgical interventions for tumor cytoreduction. The case presented, according to specialty literature, is the second one as far as volume and weight of the tumor go, the tumor invading the peritoneal cavity and weighing in at approximatively 15 kg. KEY WORDS: Gist, Second largest tumor, Tyrosine-kinase inhibitors, Nuclear pleomorphism.