Abstract:A new geographical distribution record of the invasive species of Redbelly Tilapia, Coptodon zillii, is reported here from a drainage in southern Iran, based on the discovery of a population at Howba spring. The locality of the new record is now completely dominated by this exotic fish; this location was previously inhabited by native fishes. As tilapia species have a high resilience to harsh environmental conditions, they can easily be translocated to, and establish in, new habitats. Thus, ecological monitoring of this exotic fish species is highly recommended.