One major goal of post-genomic biology is to understand the function of genes. Many gene functions are comprehensible only within the context of chemical communication, and this symposium seeks to highlight emerging research on genomics and chemical communication and catalyze further development of this highly productive interface. Many of the most abundantly represented genes in the genomes characterized to date encode proteins mediating interactions among organisms, including odorant receptors and binding proteins, enzymes involved in biosynthesis of pheromones and toxins, and enzymes catalyzing the detoxification of defense compounds. Determining the molecular underpinnings of the component elements of chemical communication systems in all of their forms has the potential to explain a vast array of ecological, physiological, and evolutionary phenomena; by the same token, ecologists who elucidate the environmental challenges faced by the organisms are uniquely well-equipped to characterize natural ligands for receptors and substrates for enzymes. Thus, partnerships between genome biologists and chemical ecologists will likely be extremely synergistic. To date, these groups have rarely had opportunities to interact within a single forum. Such interactions are vital given the considerable practical benefits potentially stemming from these studies, including the development of biorational products for agricultural and forest pest management, for disease treatment, and for improving the quality of ecosystem health.