Gastric cancer is the fourth most common cancer in the world. Most gastric cancers are diagnosed in advanced stages, and the prognosis remains poor. The 5-year survival rate is 40-60% in eastern countries and around 25% in the west. Among advanced gastric cancer cases, peritoneal implantation is one of the most common forms of metastasis and around 14% of cases present peritoneal metastases at initial diagnosis, presenting a survival of 3-6 months. Until the early 1990s it was considered a terminal disease. But today these patients have some opportunities to be treated with curative intent or to prolong their life. Although the prognosis remains poor, there are some treatment options including cytoreductive surgery, neoadjuvant therapy, and some forms of intraperitoneal chemotherapy with or without hyperthermia. These are aggressive treatments, so we must be careful when selecting patients. Imaging and preoperative staging are also crucial in selecting patients for appropriate treatment. The surgical technique is described and a detailed demonstration video is available in the e-book version. New forms of treatment such as PIPAC and new scientific advances and future perspectives are discussed. This book is an update on this topic and attempts to provide an overview for all medical personnel involved in the treatment of these patients.