After forcing two early corners Mansfield were found wanting when on-loan Bolton striker Cleveland Taylor broke down the right, but he lacked support and the attack petered out.
Scunthorpe kept up the pressure and Paul Hayes should have done better with a header that was wide of the mark.
The Stags hit back but Liam Lawrence and Iyseden Christie got in each others way as Tom Evans looked uncertain.
For a long period the game appeared to be going nowhere, with Steve Torpey's inaccurate and weak shot straight at Kevin Pilkington the best it got for United.
Mansfield then had the best chance, after 38 minutes, when Bobby Hassell broke through to crash a shot against an upright.
Scunthorpe showed greater promise in the second half and the Stags found themselves on the back foot.
Cliff Byrne and Taylor went close for the Iron while Hayes directed a header just over the bar.
Mansfield's best effort came when Neil Mackenzie was inches wide but it was the on-loan Taylor who provided some sparks in the closing stages.
He was unlucky to crash a shot against the woodwork and in the closing stages Kevin Sharp's left-foot cracker came back off the post.
Both sides felt they were denied penalties, but the referee was in a lenient mood and took no action.