Stoke fought back twice at New York Stadium to stretch Rotherham's winless run to four games.
The Millers went ahead just before half-time when Wes Harding's effort deflected in off Stoke midfielder Jordan Thompson.
Tyrese Campbell equalised for the visitors, only for substitute Conor Washington to restore Rotherham's lead.
But Stoke secured a draw when Lee Peltier headed into his own net 10 minutes from time.
Alex Neil's side carved out the bulk of the chances during an even first half, with Millers' goalkeeper Viktor Johansson called into action twice to thwart Campbell.
Campbell combined effectively with Liam Delap, who almost opened the scoring with a shot on the turn, only to be denied by Peltier's timely challenge to divert the ball harmlessly into Johansson's gloves.