In recent years, a significant number of novel metabolites with potent pharmacological properties have been discovered from the marine organisms. The marine environment harbors several macro- and microorganisms that have developed unique metabolic abilities to ensure their survival in diverse and hostile environments resulting in the biosynthesis of an array of secondary metabolites with specific activities. The sponge is one of the oldest multicellular invertebrates in the world. Marine sponges have proved to be a prolific source of unique bioactive secondary metabolites. Among them alkaloids and terpenoids displayed the most diverse biological activities including antibacterial, antifungal, anticancer, antiinflammatory, and cardiovascular activity. This chapter is specifically aimed at reviewing the biology and chemistry of compounds isolated from marine sponges.