Most cases of gastric cancer in Europe are detected in the advanced stages. The recommendations concerning diagnostic and therapeutic procedures currently in effect were presented during the 1st St. Gallen EORTC Gastrointestinal Cancer Conference in St. Gallen, in March 2012. The indispensable diagnostic tests are endoscopy with histopathological assessment of endoscopic biopsies, and CT scan of the abdomen and the chest. In the case of locally advanced gastric cancer the basis of treatment is a resection procedure. The type of surgery performed depends on the size of tumour (cT) and the state of lymph nodes (cN). In tumours cT2-4a and/or cN+ a total or subtotal gastrectomy is an obligatory step. Clinical studies carried out recently have confirmed that patients with locally advanced tumours – depth of invasion T2, T3, T4 and/or N+, without the presence of distant metastases – should be eligible to receive neoadjuvant chemotherapy. Adjuvant therapy following surgical resection after the resection surgery consists in the continuation of chemotherapy or application of radiotherapy. Postoperative chemotherapy prolongs the 5-year survival rate by 13–14%, and the use of adjuvant radiochemotherapy increases the percentage of overall survival by 11%.