The use of indocyanine green (ICG) to measure liver function, has been around for a few years now, but was introduced in Debrecen in April 2013. ICG clearance tests were performed pre- and postoperatively and in 19 patients with various hepatic pathologies, sub-grouped into 10 candidates for liver resection and 9 who were suffering from acute liver failure. Based on the trends in the study, we are able to determine an appropriate treatment plan with good outcomes in surgical cases and detect liver failure in time to prevent further complications or manage sequelae of failure.