The liver fluke is a highly pathogenic flatworm parasite of grazing livestock, causing considerable animal health and welfare issues and significant economic losses to the livestock industry. It has a complicated life-cycle, involving a tiny mud snail intermediate host. As a result, fluke prevalence, seasonality and geographic spread are very much driven by the prevailing weather conditions, especially rainfall. Following one of the wettest summers on record last year, many farmers experienced significant losses due to liver fluke over the winter months of 2012-2013, with sheep farmers particularly badly hit. This presentation will describe the liver fluke’s complicated life-cycle, the role of climatic and other factors in its spread and implications for its management and control. Liver fluke is notoriously difficult to diagnose in the live animal, the various diagnostic options and their relative advantages and disadvantages will be explored. Finally, new developments, such as the emergence of rumen fluke, and recent fluke research findings will be discussed.