Sexually mature females of the German cockroach call and emit a volatile sex pheromone from their pygidium, the last abdominal tergite. This pheromone attracts conspecific males from a distance. Upon contact with the female, a contact sex pheromone on the female’s cuticular surface elicits courtship responses in males. We dissected and extracted thousands of pygidia from sexually mature females, fractionated the extracts by flash chromatography, HPLC, and preparative GC-EAD, and subjected the purified female pheromone to GC-MS and NMR. Elucidation of the chemical structure of the pheromone was then verified by its organic synthesis. The synthetic pheromone was highly attractive in two-choice olfactometer assays in the lab and in trapping experiments in a cockroach infested pig farm. This novel volatile pheromone offers a new tool for detection, population monitoring, and, in combination with insecticides and biological control agents, for cockroach control.