Asked if he thought it would be a problem to take a meeting described to him as part of a Russian government effort to aid his father, Trump Jr. said no.
The meeting - and whether President Trump knew about it - has become a central focus of Mueller's investigation into Russian meddling in the 2016 election, as well as the congressional Russia investigations.
"No, I did not", Trump Jr. replied.
In January, Senate Judiciary Chairman Chuck Grassley said he planned to release the transcripts because the committee's interviews connected to the Trump Tower meetings had wrapped up.
Thousands of pages of interview transcripts with the participants of the June 2016 Trump Tower meeting shed new light on how eager Donald Trump Jr. and senior members of the Trump campaign were to obtain damaging information on Hillary Clinton - and how frustrated and angry they were that the material did not come to fruition.
Special Counsel Robert Mueller is also investigating.
The panel was also not able to interview Jared Kushner, Trump's son-in-law, or Paul Manafort, Trump's former campaign chairman, though both attended.
Committee Democrats said the details about the meeting revealed in the new trove of documents confirm an inappropriate relationship between Trump campaign aides and the Russian government.
His notes mention "Russian adoption by American families" and Bill Browder, a British citizen who has spearheaded a US sanctions law -known as the Magnitsky Act- that targets Russian officials over human rights abuses.
Manafort's notes also contain references to "tied into Cheney" and "active sponsors of RNC" without any further explanation. "I was aware of none", said Trump Jr., in a seemingly definitive statement within his I-don't-remember-filled interview.
Democrats on the committee have raised the possibility that father and son could have discussed the proposed meeting while Trump Jr. was in the midst of arranging it with Russian pop star Emin Agalarov and his British publicist, Rob Goldstone.
The Senate intelligence committee says it agrees with a 2017 assessment by intelligence agencies that Russian Federation intervened in the presidential election earlier to hurt the candidacy of Democrat Hillary Clinton and to help Donald Trump.
"After a few minutes of this labored presentation, Jared Kushner, who is sitting next to me, appeared somewhat agitated by this and said, 'I really have no idea what you're talking about".
The Agalarovs had bonded with the Trumps during the 2013 Miss Universe pageant in Moscow. "If I could scratch my last statement", Trump Jr. said, "yes, I did read about that after the fact". "I've just sat in a meeting about adoption".