Updated: 12:06 p.m. MT
The Westminster Democrat was facing a possible recall for her votes in favor of gun control measures.
Her opponents were expected to submit signatures in that recall next week.
In her resignation letter to the Secretary of the Senate, Hudak wrote that her leaving meant that Jefferson County taxpayers weren't "forced to pay more than $200,000 for a special election" while the county has slashed funding for a senior resource center and the Jefferson Center for Mental Health.
Her resignation means that Democrats will appoint a successor and maintain their one-seat advantage in the Senate.
“Today, the people of Senate District 19, and the entire state, lost a courageous and principled leader,” Senate President-elect Morgan Carroll (D-Aurora) said in a written statement.
One supporter of the recall effort, Dave Palm, told Colorado Public Radio that he was not happy with Hudak's decision.
"I mean if she believes in what she’s doing, and she believes that she’s representing the people and she ought to stand up and face the recall ballot," Palm said.
According to The Denver Post, about two dozen supporters of Hudak gathered outside the Arvada Public Library on Wednesday holding signs that read “Thank You Evie” to applaud the state lawmaker for her work.
Recall elections in September ousted two other Democrats for their positions on gun control bills.
Senate President John Morse (D-Colorado Springs) and Senator Angela Giron (D-Pueblo) were the first recalled state legislators in state history.
Colorado Public Radio reporter Ben Markus and the Associated Press contributed to this report.