A case of hemoperitoneum caused by a ruptured gastrointestinal stromal tumor (GIST) of the posterior gastric wall is presented. An otherwise healthy 81-year-old man presented with abdominal pain/tenderness and anemia (hemoglobin: 7.4 g/dL). Computed tomography scan showed hemoperitoneum and a gastric mass of uncertain nature. As the patient was hemodynamically stable, a mini-invasive approach was decided. Esophagogastroscopy revealed an umbilicated mass of the posterior gastric wall, therefore allowing for a correct preoperative diagnosis of GIST and its appropriate treatment by laparoscopic atypical gastrectomy. Laparoscopically, a longitudinal resection of gastric fundus including the tumor was performed in a sleeve gastrectomy fashion, 25 minutes after the induction of pneumoperitoneum. The outcome was uneventful. Pathologic examination confirmed a benign 4×3-cm gastric GIST with <1 mitosis per 50 high power field, staining positive for CD117 (C-KIT) and negative for S-100 protein and smooth muscle actin. To our knowledge, it is the first case of a successful laparoscopic resection of an endoscopically diagnosed gastric GIST in an emergency setting. Hemoperitoneum is a rare, potentially severe complication of GIST. As bleeding is rarely severe, most patients may benefit from a mini-invasive approach, even if the tumor is located in the posterior gastric wall.