The identification of HER2 alterations in advanced gastric carcinomas is critically important in daily clinical practice as such neoplasms require specific treatment with Trastuzumab. For this reason, expert pathologists and oncologists have agreed on national guidelines for HER2 testing in gastric carcinomas. The guidelines are based on the experience of the participants and pertinent recent international publications. They outline the minimum requirements for the Pathology Laboratory in order to guarantee satisfactory routine HER2 testing. The guidelines recommend that any laboratory not fulfilling such requirements make the adjustments necessary for compliance.