Yes! (if you are quick) If you delete a poll by mistake, you can recover it straight away after deletion. Simply open the admin link once more and click the button 'Restore this poll'. You can only do this within two hours after deletion.
If you lost your admin link, you can retrieve it here.
If the poll was deleted automatically, it can not be recovered.
According to our policy, outdated polls are automatically deleted from time to time, unless you have a Premium Doodle subscription. If you want to keep your polls, you have to open them from time to time to reset the timer. All infos can be found in our policy in the section on "Outdated and completed polls"