A 71-year-old female was referred to our hospital for abdominal distention and anorexia. Gastrointestinal endoscopy revealed wall thickening of the entire circumference. Abdominal CT scan showed diffuse thickening of the stomach, but there was no obvious metastasis. Scirrhous gastric cancer was strongly suspected, but endoscopic biopsies could not demonstrate malignant features. Staging laparoscopy was performed. There was a small amount of ascites and numerous peritoneal dissemination. She was diagnosed with gastric cancer pStage Ⅳ(pT4a, NX, H0, M1, P1, CY1)without HER2 positivity. We experienced a case of scirrhous gastric cancer in which staging laparoscopy was useful for histological diagnosis and staging.