Till Firefox 3, hidden settings like ''browser.history_expire_days'' were supported that allowed you to control how long the history is maintained. But, for various reasons, these settings are no longer supported. Firefox 4 and above use a heuristic algorithm to decide how long to keep the history items. See this article for more information: [http://blog.bonardo.net/2010/01/20/places-got-async-expiration Places Got Async Expiration].<BR><BR> Nevertheless, you can set the value of these hidden settings for some degree of control: * ''places.history.expiration.max_pages'': the maximum number of pages that will be retained before expiring. * ''places.history.expiration.interval_seconds'': number of seconds between each expiration algorithm run. You can change these hidden settings by following these steps: # Open a new tab and in the address bar, type '''about:config''' and then press '''Enter''' # Click the '''I'll be careful, I promise''' button # In the '''Filter''' text box at the top, type '''places.history.expiration.max_pages''' # You will be presented with the setting for ''places.history.expiration.max_pages''. # Right click on it, select '''Modify''' and enter the desired value. # Click '''OK'''. # Repeat these steps for ''places.history.expiration.interval_seconds''. <BR>Maybe there is an add-on that allows you to configure how long you wish to keep history. Search for it here: https://addons.mozilla.org/en-US/firefox/