Brzezinski began her journalism career as a volunteer of World News This Morning for ABC in 1990. Later after one year, she joined WTIC-TV, a Fox affiliate channel in Hartford, Connecticut. She was promoted to general assignments reporter from project and features editor.
In 1992, She moved to WFSB-TV, affiliated with CBS. and started anchoring after working there for three years. She left WFSB-TV in 1997 for joining CBS News as reporter and host of all night news show Up to the Minute.
Brzezinski took a break from CBS in 2001 and worked for MSNBC show Homepage along with her co-hosts Gina Gaston and Ashleigh Banfield. Their trio team was illustrated as ‘the Powerpuff Girls of journalism’ by Entertainment Weekly magazine.
In September 2001, she came back to CBS and started to serving for “Ground Zero” reporter during September 11, 2001, attacks. She was reporting live from the spot while the South Tower crashed.
She served as a fill-in anchor, news correspondent, and anchor for breaking news and schedule updates in CBS News. Before getting fired from the network she also contributed occasionally to CBS Sunday Morning and 60 Minutes.
On 26 January 2007, Brzezinski came again to MSNBC and covered the evening news show, Up to the Minutes. She then served for primetime news updates and occasionally reported for NBC Nightly News as well as fill-in host of Weekend Today.
Later when Joe Scarborough chose her as co-anchor of Morning Joe, she quit previous shows. She currently appears as newscaster and co-host of Morning Joe with Joe Scarborough and Willie Geist where her father was invited frequently as a guest. She most often tells in a show that she is a Democrat whereas Joe is a Republican.
Apart from reporting and anchoring, she is also an author and has published three books. All Things at Once was her first book printed by Weinstein Books in early 2010. Her Knowing Your Value: Women, Money and Getting What You’re Worth was about financial managements for women published in 2011. Her love for food was depicted on her third book Obsessed: America’s Food Addiction and My Own issued in 2014.
Brzezinski has dragged herself in few controversies while working in MSNBC. Once, she denied reading news on 26 June 2007 which was about the release of Paris Hilton from lockup. \
On 7 July 2010, she on-air pressurized to file a case on Lindsay Lohan and Levi Johnston. Also, on 15 February 2017, Brzezinski prohibited the upcoming arrival of Kellyanne Conway, a spokesperson of Trump accusing that she conveys fake news. She was supported by the columnist of Washington Post, Jennifer Rubin and Joe Scarborough for banning Conway’s appearance in media.
Brzezinski and Joe were unfollowed on Twitter by Donald Trump during presidential campaign 2016. Trump targeted them for calling his presidency ‘fake and failed’ in March 2017. Later in June 2017, Trump tweeted calling ‘low I.Q. Crazy Mika’ and stated she was ‘bleeding badly from the face lift’.
She was also nominated for News & Documentary Emmy Awards in 2013 for ‘Morning Joe’.