The Turkish Ministry of Justice hasidentified the existing system of expert witnesses as anobstacle to the efficiency and effectiveness of the judicialservices. The 2009 judicial reform strategy and the judicialreform action plan call for a comparative study analyzingthe experience in other countries to provide input into thepolicy debate in Turkey. This study provides descriptionsand analyses of approaches to the use of expert opinions incivil, criminal, and administrative court proceedings inFrance, Germany, Italy, and the United States. It focuses onfive key areas: access to the function of expert, executionof an expert opinion, the opinion and its use in evidence,remuneration, and liability.