In the Far East and Pacific, there has been a long tradition of consuming seaweeds as sea vegetables, while in Western countries the principal use of seaweeds has been as source of phycocolloids (alginate, carrageenan and agar), thickening and gelling agents for various industrial applications, including uses in foods. In addition, seaweeds constitute an interesting source of compounds with health protective effects. This paper is a short review on the biochemical composition and the nutritional value of seaweeds.