"In 1974, I announced my first campaign for Congress," Waxman said in a statement. "Today, I am announcing that I have run my last campaign. I will not seek re-election to the Congress and will leave after 40 years in office at the end of this year.
The 74-year-old Democrat who represents California's 33rd Congressional District, which includes western Los Angeles, Malibu, Santa Monica and West Hollywood, said he is proud of his legislative accomplishments and is grateful for the support of his constituents who encouraged him to become a leader on national and international issues, including the enactment of major health, consumer protection, environmental, telecommunications and good government laws.
"I first ran for office because I believe government can be a force for good in people's lives," he said. "I have held this view throughout my career in Congress. And I will leave the House of Representatives with my conviction intact. I have learned that progress is not always easy. It can take years of dedication and struggle. But it's worth fighting for."
Waxman, however, said there are elements of today's Congress that he does not like.
"I abhor the extremism of the Tea Party Republicans. I am embarrassed that the greatest legislative body in the world too often operates in a partisan intellectual vacuum, denying science, refusing to listen to experts, and ignoring facts."
"But I am not leaving out of frustration with Congress. Even in today's environment, there are opportunities to make real progress," he said.
The Los Angeles-native said he is also not leaving because he thinks Democrats are unable to retake the House.
"The reason for my decision is simple. After 40 years in Congress, it's time for someone else to have the chance to make his or her mark, ideally someone who is young enough to make the long-term commitment that's required for real legislative success."
The Washington Post said the liberal Waxman played a crucial role in a number of important laws, including one to make infant formula safer and more nutritious in 1980, bringing low-priced generic drugs to the market in 1984, cleaning the air in 1990, providing services and medical care to people with AIDS in 1996 and reforming and modernizing the U.S. Postal Service in 2006.
Waxman also was instrumental in the 2010 passage of the Affordable Care Act, aka Obamacare, the newspaper said.
"Everything I ever passed into law, with one exception, had bipartisan support," he told the Post. "And the exception was the Affordable Care Act, where the Republicans should have been working with us but didn't want to give President Obama a victory even though the law was based on a lot of Republican ideas."
Waxman and his staff also led investigations into tobacco industry marketing practices, the use of steroids in professional sports, the 2008 collapse of Wall Street and the flawed intelligence used to justify the Iraq war, the Post said.