  We review recent studies of organic molecule formation in dense molecular
clouds and in comets. We summarise the known organic inventories of molecular
clouds and recent comets, particularly Hale-Bopp. The principal chemical
formation pathways involving gas phase reactions, as well as formation by
catalytic reactions on grain surfaces or through dust fragmentation, are
identified for both dense clouds and cometary comae. The processes leading to
organic molecules with known biological function, carbon chains, deuterium
fractionation, HNC and S-bearing compounds are described. Observational
searches for new interstellar organics are outlined and the connection between
observed interstellar organics and those detected in comets Hale-Bopp and
Hyakutake are discussed.
