"We still have an important role in oversight, I'm not going to dismiss it," Chaffetz told a group of reporters Monday.
"My job is not to be a cheerleader for a president, my job is to hold them accountable," he continued.
Chaffetz said the committee will continue some outstanding investigations, including the probe into Hillary Clinton's use of private email while serving as secretary of state, which he called "very important," and review of the Fast and Furious gunrunning operation.
"Just because there's an election doesn't mean this goes away," Chaffetz said.
"It cannot, and should not be repeated ever again," he said of her private email use while serving as the country's top diplomat.
Armed with subpoena power, Chaffetz and his powerful committee has a broad mandate to conduct oversight across the federal government.
But he said he will be watching Trump's press conference where he plans to announce his plans for his business interests later this week.
Even though Trump, as president, will be exempt from conflict-of-interest law, Chaffetz said his "concern is to make sure there is compliance with the law."
He also said he's planning to meet with incoming White House counsel Don McGahn, and has to review anti-nepotism statutes following news that Trump's son-in-law will join the White House as an adviser.
"That's going to draw some questions, and it will for us as well," Chaffetz.
Now, working under a GOP president is a "big test for me," he said.
He the committee will also focus on investigating sexual harassment in the government, the federal retirement system and postal reform, among other issues.