Gastric cancer is still one of the predominant causes of death on account of gastrointestinal neoplasias. In recent years, chemotherapy and radiotherapy have substantially improved the outcome in operable gastric cancer patients. A benefit in median overall survival is reported for perioperative chemotherapy as well as for postoperative adjuvant radio-chemotherapy. But there is still a controversy about the best treatment sequence. The aim of this paper is to critically review current literature, to discuss the pros and cons of neoadjuvant (preoperative) or postoperative adjuvant therapy and to give treatment recommendations based on large phase III trials.