Pheromones are utilized by many insects in a complex chemical communication system. This review will look at the biosynthesis of sex and aggregation pheromones in the model insects, moths, flies, cockroaches, and beetles. The biosynthetic pathways involve altered pathways of normal metabolism of fatty acids and isoprenoids. Endocrine regulation of the biosynthetic pathways will also be reviewed for the model insects. A neuropeptide named pheromone biosynthesis activating neuropeptide regulates sex pheromone biosynthesis in moths. Juvenile hormone regulates pheromone production in the beetles and cockroaches, while 20-hydroxyecdysone regulates pheromone production in the flies.