Alfie Beestin scored his first ever league goal to give Doncaster the lead before half-time but Ryan Edwards equalised deep into the second half.
John Marquis missed a glorious chance to give Rovers the lead midway through the first half when racing clear only to see a tame effort batted away by Remi Matthews.
Doncaster would go ahead after 37 minutes, however, when Beestin clipped in a sublime half volley after latching onto a pass from Tommy Rowe.
The hosts started the second half the stronger but Plymouth soon began to threaten.
It took a goalline clearance from Matty Blair to keep out a powerful header from Sonny Bradley, while Ryan Taylor fired narrowly wide from the edge of the box.
But Argyle did level after 74 minutes. David Fox curled a free-kick to the far post where Edwards drilled a volley home from close range.
The visitors looked the more likely to snatch the win with Antoni Sarcevic drawing a fine save from Ian Lawlor as the spoils were shared to leave both sides sitting midtable with 35 points.
Preston are reportedly weighing up whether or not to make a fourth offer for Peterborough United left-back Andrew Hughes.
James Maddison has completed his move from Norwich City to Leicester City for an undisclosed fee.