Stilbenes are a small family of plant secondarymetabolites derived from the phenylpropanoid pathway, and produced in a number of unrelated plant species. These compounds have numerous implications in plant disease resistance and human health. This review first presents the stilbene biosynthesis pathway and recent advances in the characterization of stilbene biosynthetic genes in different plant species. A large body of evidence indicates that stilbenes participate in both constitutive and inducible defense mechanisms in plants, however, the detailed functions of these compounds have not been fully elucidated. The second part of this review discusses known functions of stilbenes in plants, especially in plant–pathogen and plant–herbivore relationships, or in plants subjected to abiotic stresses.