Se describe e ilustra Peucetia cauca (Araneae, Oxyopidae) de Colombia. Se trata de la cuarta especie del género descrita para Colombia y la primera araña completamente fluorescente que se describe.Peucetia cauca (Araneae, Oxypidae) from Colombia is described and illustrated.  This is the fourth species of the genus described from Colombia and the first fully fluorescent externally spider to be described.