Oh, I forgot that you need to: MimeTypes.LoadFromFile(AMimeTypesFile); first. -- View this message in context: http://free-pascal-lazarus.989080.n3.nabble.com/Lazarus-Function-to-get-the-mimetype-from-a-file-extension-tp3973851p3973969.html Sent from the Free Pascal - Lazarus mailing list archive at Nabble.com.