http://kb.mozillazine.org/Lost_bookmarks First check the dates on what is available on the backups that firefox stored in your current profile Ctrl+Shift+B > Import & Backup > Restore check the dates on json files, and on places.sqlite when you check other profiles up one level from your current profile. You can get to the current profile typing '''about:support''' into the location bar > "Open Containing Folder" and noting the filename (contains profile name) and then going up one level to the profiles directory to see other profiles.