this paper reviews available information on secondary metabolites (sm) of plants from arid environments. we describe sm′s classification, chemical composition, and prospective plant families for the production of each group of compounds, namely alkaloids, terpenes, latex, rubber and waxes. the role of sm as chemical defenses, allelochemicals and signal molecules to attract pollinators, as well as their contribution to uv-protection and in water economy, at plant and community levels are discussed. theories explaining the origin of sm (growth-differentiation balance and carbon-nutrient balance hypotheses) are depicted. release mechanisms of ms in the environment, decomposition and incorporation of these compounds into the soil are described. in the last part, industrial uses of sm, present or potential, are summarized. this paper is focus on sm produced by plants native to arid and semiarid environments.