Not as a ,pst file as Thunderbird has no idea what Microsoft specific file means. If.pst file contains emails: you would need to convert the .pst file to mbox file and then import the mbox file using this addon tool: * https://addons.mozilla.org/en-US/thunderbird/addon/importexporttools/ However: If you have Outlook email client on your computer please try this: Set 'Outlook' as default In Thunderbird Tools > Import select 'Mail' and click on Next Select 'Outlook' and click on Next -------------------------- If you are talking about Address Book info: then in thunderbird: Tools > Import select: Address books and click on Next select: Outlook and click on Next Otherwise: In 'Outlook', export the address book as a .csv file Then in Thunderbird Tools > Import select: Address books and click on Next select: Text file (Ldif, .tab , .csv, .txt) and click on Next locate saved .csv file and click on Open you may need to map the fields. additional help: * http://kb.mozillazine.org/Import_.pst_files * http://kb.mozillazine.org/Import_from_Outlook_Express