Ambergris is a rare substance produced in the intestines of sperm whales. It appears to result from an irritation caused by the beaks of the cephalopods on which they feed. The link between ambergris and whales, if not the mechanism by which ambergris is produced, has been addressed throughout history but, due to contradictory reports and fanciful explanations regarding its origin, only recently has it been widely accepted. Since ancient times ambergris has been used for medicinal purposes and in perfumes, but its supposed exotic properties are an important reason for the European demand for this substance. Accounts about ambergris from places where Europeans sailed since the 15th century are numerous. In the 16th and 17th centuries there were no laws dictating who owned the ambergris found on beaches and many pieces were sold or traded, legally or illegally, from overseas to Europe. However, this product was always obtained in relatively small quantities. More recently, with the advent of industrial whaling dedicated to sperm whaling conducted by several nations in various parts of the world during the 19th and 20th centuries, ambergris acquired an importance of its own and was sold at very high prices. In the Azores, ambergris from hunted sperm whales was documented; the same applies for Madeira and the Portuguese mainland. Being a product typically reported in whaling data and related to the economic exploitation of the sea, it is through the historical sources that its importance is clearly demonstrated.