Objective We are aiming to study the expression of human epidermal growth factor 2 (HER2) in gastric carcinoma (GC) to estimate the susceptibility for target therapy by trastuzumab hoping to improve the outcome especially in late stage cases. Materials and methods This is a retrospective study that included 50 cases diagnosed as GC in Benha University hospital. Our study included an examination of the endoscopic biopsies of 40 cases and the resection specimens of 10 cases. We assessed HER2 status by application of immunohistochemistry to all the cases. When cases were equivocal on immunohistochemistry, we applied fluorescence in-situ hybridization. The collected data were statistically analyzed. Results HER2 was positive in 17 (34%) cases. It was statistically significant (P