Identified dorsal unpaired median (DUM) neurones of the locust Locusta migratoria were stained intracellularly with large amounts of cobalt to reveal their extensive peripheral branching patterns. Two neurones of the suboesophageal ganglion were studied as well as several neurones of thoracic ganglia. The peripheral branching pattern of all these neurones is described completely. As expected, the prevalent target organs of all DUM neurones are skeletal muscles. In addition several, but not all DUM neurones studied here form neurohaemal release sites on the surface of peripheral nerves and thus represent potential sources for octopamine acting as a neurohormone.