Tykes boss Markus Schopp made two changes, with Claudio Gomes and Clarke Oduor replacing Romal Palmer and Dominik Frieser, who was named among the substitutes.
The Blackburn line-up showed one change as Ian Poveda took over from Leighton Clarkson.
Early on, Barnsley’s Toby Sibbick chipped the ball into the area, aiming for Cauley Woodrow, but it went just beyond the striker.
Oduor then went close to scoring a fine individual goal, producing a mazy run into the area before firing in a shot which was saved by Thomas Kaminski.
A couple of promising openings for the visitors came to nothing when Tyrhys Dolan and Ben Brereton Diaz both sent over inviting crosses but there was no one to apply the finishing touch on either occasion.
Michal Helik directed a header on target after meeting a corner from Woodrow, but Kaminski was able to make a comfortable save.
Schopp made two changes to his Barnsley line-up for the start of the second half, with Frieser and Will Hondermarck taking over from Sibbick and Aaron Leya Iseka.
There was another change for Barnsley on the hour mark when Gomes made way for Victor Adeboyejo.
A powerful run from Helik saw him upended before he was able to reach the D and the resulting free-kick, taken by Woodrow, was deflected wide off the defensive wall.
Blackburn boss Tony Mowbray made a double substitution midway through the second half, with Dolan and Poveda replaced by Clarkson and Reda Khadra.
Kaminski made a great save to keep out Frieser’s header following a corner.
Blackburn also went close soon afterwards when Brereton Diaz found himself through on goal, but he was denied by Brad Collins who came to his side’s rescue with an important block.
Barnsley’s Callum Brittain volleyed wide as the action continued to go end to end and another substitution for the visitors saw Joe Rothwell make way for Tayo Edun.
The home side went desperately close to scoring when Helik’s flicked near-post header just evaded the stretching Adeboyejo and the ball went a fraction beyond the far post.
Both sides went in search of a late winner, with Barnsley’s Callum Styles putting a 30-yard drive wide before Collins was forced to save an effort from Clarkson, who was set up inside the area by Khadra.