 Aspiration of gastric content is a rare but serious complication of anesthesia. In this context, preoperative fasting for elective surgery is well defined. In an emergency situation, international guidelines recommend rapid sequence of anesthesia to reduce the risk of aspiration. In semi emergency situation, there is no consensus about the anesthetic procedure even if a preoperative fasting has been observed due to uncertainty of gastric emptying related to stress or painful condition. The choice of anesthesia induction technique depends mainly on the anesthetist. Ultrasonography is a non invasive bedside tool that can provide reliable quantitative information about the volume of gastric content. 