At present, the total output of the world's seaweed industry amounts to around US$6 billion, with more than 8 million tonnes of wet seaweed used annually. Seaweeds are widely used as food but are also an important ingredient for the cosmetics industry. They also serve to produce hydrocolloids (alginate, agar and carrageenan), which are used as thickening and gelling agents. This document highlights the rising importance of seaweed farming and shows how an essential Asian food has become popular in North and South America as well as in Europe. The report will be useful to those who wish to know more about the seaweed industry, about the markets for commercial seaweeds and about the various sources and methods of production. It is written with a minimum of technical language and is designed to assist in making decisions concerning seaweeds and the seaweed industry.