Rob Hulse missed an open goal in the second half as both sides failed to find a decisive goal, taking the fiercely contested FA Cup quarterfinal into a replay at Ewood Park.
With a place at Wembley Stadium up for grabs, both sides made tentative starts to the game. Much of the first quarter of the match was punctuated by fouls and free kicks as both sides did more to disrupt the other's attack instead of building their own.
Backed by a home crowd, it was Kenny Jackett's Millwall side that eventually took the intiative and started to apply some pressure on Blackburn. The Lions had the ball in the net just before the half hour mark, but Rob Hulse's goal was ruled out because of a foul.
The hosts had the best chance of the half in the 37th minute, when Jack Smith burst forward down the left before curling a right-footed cross in towards the post. Andy Keogh, though, could only head on to the inside of the post.
Blackburn boss Michael Appleton must have had some inspiring words for the visiting side at halftime, because Rovers came out a reinvigorated side in the second half.
They should have taken the lead moments after the break through Jordan Rhodes, but the normally clinical striker flashed his shot from a tight angle over the bar from a few yards out.
That scare sprung the home side back into life, and the Millwall twice went close to scoring in response.
Danny Shittu almost lifted the roof off the stadium with a rasping effort from all of 40 yards, but his audacious effort was tipped over by Blackburn goalkeeper Jake Kean.
Hulse then had a glorious chance to give the Lions the the lead but somehow managed to turn Keogh's cross over the bar with an open goal gaping at his mercy.
Joshua King struck the woodwork for Rovers after a goal-mouth scramble in the 80th minute but it was Millwall who applied all the late pressure with the help of the raucous home support. Despite the hosts' best efforts, they were unable to find the breakthrough, taking the tie to a replay at Ewood Park with the winner advancing to a Wembley Stadium semifinal.