A staple in Asian diets since ancient times, seaweed is nutritionally dense, packed with vitamins, minerals, and antioxidants. The health properties of seaweed are thought to be attributed to unique features of the marine environment where they grow. Seaweed is rich in some health-promoting microcomponents such as dietary fiber, ω-3 fatty acids, essential amino acids, and vitamins A, B, C, and E. In this chapter, the nutritive value of seaweed focusing on various lipids, bioactive carbohydrates, minerals, vitamins, and other minor constituents will be discussed.