Just wondering if you can poison a conjured weapon in Oblivion.

Yes, you most certainly can! :foodndrink:

It's why conjuration is an interesting major for a stealth assassin character, from a rp perspective. You can get past a pat-down from the guards, but still conjure up a weapon once inside and pour on that vial of poison you hid in your hair and take out your target, tipping the guard on your way out