Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. It is solid, colorless, and odorless and highly soluble in water. Urea is widely used in fertilizers as a convenient source of nitrogen and also an important raw material for the chemical industry. In this book, the authors discuss the synthesis, properties and uses of urea. Topics included in this compilation are the production of granular urea as nitrogenous fertilizer; urea and urea transporter physiology; urea transport in fungi and plants; urea used as the neutralizing agent for homogenous precipitation; the effect of urea on polymer films, natural fibers wood and jute plastic composites; pharmacological recognition of urea derivatives in brain disorders; non-bonding properties of urea; valproyl urea; and urea as an effective therapeutic option syndrome of inappropriate antidiuretic hormone secretion (SIADH).