Cone snails are marine gastropods belonging to the genus Conus that inhabit in tropical habitats throughout the world. They are predators that paralyze their prey by injection of venom, containing a complex mixture of conopeptides. The venom of cone snails has been found to be a valuable source of specific drugs for disorders ranging from stroke to chronic pain. For this work, the venom of Conus nux, a Panamic cone snail species, was extracted and analyzed. Components of the venom were isolated using Size Exclusion Chromatography (SEC) and Reversed Phase High Performance Liquid Chromatography techniques. A novel conopeptide sequence, determined by Edman Degradation is reported. The arrangement of the cysteines residues within this sequence suggest that it member of the M-superfamily of conotoxins.