Nausea and vomiting are amongst the most common and distressing symptoms observed in a variety of conditions such as pregnancy, peptic ulcer, gastrointestinal infections, gastrointestinal obstruction etc. The emesis consists of retching and vomiting. The retching is characterized by attempt to vomit without expulsion of the contents of upper gastrointestinal tract. During retching muscles of diaphragm and abdomen contract and relax simultaneously. The vomiting consists of more sustained abdominal contraction in coordination with intercostal muscles and muscles of larynx and pharynx. The glottis is closed, the soft palate elevated, the gastric fundus relaxes and contents of stomach, both solid and liquid, are forcefully expelled out through the nose or mouth. The occurrence and frequency of retching and vomiting can be measured objectively. To further elaborate the understanding of the pathways involved in generation of the sensation of nausea and reflex vomiting, to identify pharmacological approaches for development of new antiemetics and to understand the underlying problems in diseases with nausea and vomiting, as the cardinal features use of appropriate animal models is required.