Tilapia lake virus (TiLV) is a recently described virus affecting wild and farmedtilapines. At present, it has been reported on three continents (Asia, Africa andSouth America) and the number of countries where the agent has been detected islikely to increase rapidly as a result of increased awareness, surveillance and avail-ability of diagnostic methods. Any lack of openness regarding the TiLV status of atranslocating live tilapia population destined for aquaculture may inadvertentlycontribute to the spread of the agent. Currently, there is no cure for viral diseasesin aquaculture and while vaccines and selective breeding have proved successfulin reducing the severity of some viral diseases, there are currently severe knowl-edge gaps relating to TiLV and no effective, affordable vaccines are yet available.This paper summarizes the published scientific information on TiLV and high-lights important issues relating to its diagnosis, mitigation and control measures.