Doncaster will be more than happy with their point, as they played for the whole of the second period with ten-men as Abdoulaye Meite was given a straight red late in the first-half.
Meite was given his marching orders following his mistimed challenge on Stefan Maierhofer, but Millwall could not make their numerical advantage count.
Sam Johnstone was inspired in the visitors' goal - the Manchester United loanee made superb saves to deny Shaun Williams and Steve Morison in the second half.
The draw keeps both sides out of the relegation zone and locked on 44 points each, with Birmingham and Blackpool one point back in the battle to beat the drop.
The Lions are still searching for their first home win since January but they started the brighter of the two sides when Scott McDonald collected a Maierhofer flick, but his close-range shot deflected wide off Gabriel Tamas for a corner.
Lee Martin was a constant outlet for the hosts, cutting inside from both wings as the Lions controlled an attritional opening period.
Carlos Edwards surged forward on 30 minutes but blazed over the crossbar, a let off for Doncaster after centre-half Meite was caught napping in possession.
Meite atoned for his mistake when he planted a superb forward lunge in the box to dispossess Martin, but the game changed moments before half-time when the Ivorian was given a straight red for a full-blooded challenge on Maierhofer.
The Lions striker was first to a forward ball but, before he could spread possession, Meite dived in with a high, mistimed tackle, leaving referee Fred Graham no choice but to show a red card.
Millwall made their one-man advantage count after the break as the home side laid siege to the Doncaster box - Williams' long-range effort forcing a magnificent arcing save out of Johnstone.
The keeper then tipped a thunderous Morison volley over the bar before watching the former Norwich striker head a deep corner against the frame of the goal.
At the other end, Doncaster had a big claim for a penalty dismissed when Lions goalkeeper David Forde fumbled a cross and bundled striker Chris Brown over, while David Cotterill drilled wide from the left wing.
A last-ditch challenge from Rovers' impressive Paul Quinn prevented Simeon Jackson tapping into an open net 10 minutes from time.
The bombardment continued as Doncaster pulled all 10 men back. Cotterill had a chance from a free-kick 30 yards out, but the winger could only find the empty seats behind the goal.
Tempers flared as the Lions desperately strived in vain for the winner - Martin had a golden chance plucked from under his feet just yards out and Jackson's elaborate backheel failed to find a blue shirt in the box.