![Dismissed Dismissed](https://cdn.extendoffice.com/images/stories/doc-outlook/retrieve-dismissed-reminders/doc-retrieve-dismissed-reminders-2.png)
Your question asks to 'retrieve all dismissed reminders'. I am not sure if, by 'retrieve', you mean to view a list of all dismissed reminders or if you want to 'undismiss' them. I've been looking for a solution to the latter for a long time and just now stumbled upon it. You first open the meeting or appointment (I double-click the event in my calendar).
At the top, you will see this: If you dismissed the reminder then the Reminder field will say None. Change it to a new interval and then click Save & Close. You should get the reminder again. I accidentally dismissed some old reminders and the other answers didn't work for me for recovering them, so I restored a recent backup and reverted to that temporarily which brought them up. If you don't have a backup, there's a possibility you can use the 'Restore previous versions' option in the right-click menu of the PST file (or its parent folder) in Windows explorer to get a recent version. To be safe, I closed Outlook, backed up my current PST, and disabled my network connection before restoring the old PST.
Sep 15, 2011 - Earlier today, I blitzed 160 reminders by hitting dismiss all. Is there any way to get them back? Thanks for any help.