Tilapia lake virus (TiLV) is an emerging infectious agent that has recently been identified in diseased tilapia on three continents. At the time of writing, scientific publications have reported TiLV in samples collected from Colombia, Ecuador, Egypt, Israel and Thailand. While the link between TiLV and disease outbreaks in Israel and Thailand are well documented, further investigations are being undertaken to determine the significance of TiLV in the other countries. Israel and Taiwan Province of China have made a notification of TiLV as an emerging disease to the World Organisation for Animal Health (OIE). Studies have shown that populations infected with TiLV show variable levels of morbidity and mortality. This report summarizes the currently available scientific information on TiLV, including clinical signs, diagnostics and epidemiology. While of no concern to human health, the consequences of infection with TiLV in tilapia populations may potentially result in socio economic losses and impacts on food security.