Dyspepsia and functional dyspepsia represent a highly significant public health issue. A good definition of dyspepsia is key for helping us to better approach symptoms, decision making, and therapy indications.During the last few years many attempts were made at establishing a definition of dyspepsia. Results were little successful on most occasions, and clear discrepancies arose on whether symptoms should be associated with digestion, which types of symptoms were to be included, which anatomic location should symptoms have, etc.The Rome III Committee defined dyspepsia as "a symptom or set of symptoms that most physicians consider to originate from the gastroduodenal area", including the following: postprandial heaviness, early satiety, and epigastric pain or burning. Two new entities were defined: a) food-induced dyspeptic symptoms (postprandial distress syndrome); and b) epigastric pain (epigastric pain syndrome). These and other definitions have shown both strengths and weaknesses. At times they have been much too complex, at times much too simple; furthermore, they have commonly erred on the side of being inaccurate and impractical. On the other hand, some (the most recent ones) are difficult to translate into the Spanish language. In a meeting of gastroenterologists with a special interest in digestive functional disorders, the various aspects of dyspepsia definition were discussed and put to the vote, and the following conclusions were arrived at: dyspepsia is defined as a set of symptoms, either related or unrelated to food ingestion, localized on the upper half of the abdomen. They include: a) epigastric discomfort (as a category of severity) or pain; b) postprandial heaviness; and c) early satiety. Associated complaints include: nausea, belching, bloating, and epigastric burn (heartburn). All these must be scored according to severity and frequency. Furthermore, psychological factors may be involved in the origin of functional dyspepsia. On the other hand, it has proven very difficult to establish a clear correlation between symptoms and pathophysiological mechanisms.