Neither side impressed in a drab first half but both upped the tempo in an improved spectacle in the second period.
Reading threatened briefly but were indebted to goalkeeper Adam Federici, who made two superb saves from Patrick Bamford and Kike near the end to force the draw.
Middlesbrough went into the game with the best defensive record in the Championship, just 17 goals conceded in 24 matches.
And since they lost 1-0 to Reading at the Riverside Stadium in August, they had suffered only two league defeats in 19 outings.
Reading’s poor form, which led to the dismissal of manager Nigel Adkins last month, had improved under his successor, Steve Clarke.
The Royals were unbeaten in three matches, which included successive wins over Norwich and, in the FA Cup third round, Huddersfield.
Middlesbrough’s defensive organisation was evident early on, with Reading barely able to land a blow.
The visitors were also efficient going forward, with Jelle Vossen setting up Adam Reach for a shot that thundered into the side-netting.
Reach should have done better soon after when Albert Adomah found him in space at the far post.
But with the goal gaping, and under pressure from home defender Chris Gunter, Reach blazed his effort over the crossbar.
Middlesbrough continued to press and Bamford’s 20-yard drive was well saved by Federici. Adomah had a close-range attempt deflected wide before Reading finally responded, but only with a tame header from Pavel Pogrebnyak that drifted well wide.
After a lukewarm first-half showing, Reading gradually improved in the second period, mainly through the hard work of Pogrebnyak.
Jordan Obita slung over a free kick from the left and Pogrebnyak rose highest but could only direct his header over the crossbar.
Simon Cox then released Hal Robson-Kanu but Middlesbrough keeper Dimitrios Konstantopoulos dived bravely at his feet to gather the ball.
Reading were gathering momentum, with centre back Michael Hector nodding narrowly wide from an Oliver Norwood corner.
The home side went close again as Middlesbrough were pegged back for the first time in the game.
Alex Pearce somehow missed Norwood’s dangerous free kick and as the ball rebounded off Hector at the far post, Konstantopoulos gathered safely.
Konstantopoulos was soon in action again, stooping to collect a low shot from Norwood that lacked power.
Middlesbrough survived the pressure and almost went ahead in the 66th minute from a Grant Leadbitter free kick.
Adomah powered in a header in the midst of a packed home area but Federici made a stunning reaction save to parry the ball away.
Federici then frustrated Middlesbrough again when superbly tipping Bamford’s 25-yard piledriver on to the bar and, from the corner, also doing well to keep out Kike’s firm header.