Abstract: A safety coupling pin for securing a towed vehicle tongue to the towing vehicle drawbar using a shaft which is secured by a chain. A ring affixed to one end of the shaft has an opening which is normally closed by a spring loaded cylinder. The chain has one end permanently attached to the ring and the free end can be attached or disconnected to the ring through the opening by moving the cylinder. In use the shaft is inserted into aligned holes in the tongue and drawbar from the top and the chain secured under and around the tongue and drawbar by connecting the free end through the ring to secure the pin in place.