Between 1976 and 1990, she was stationed with the ANC in exile outside South Africa; during this period, she was also a prominent cultural activist as a poet and the head of the Medu Art Ensemble.

[6] In addition to her work with the Women's Section, she was involved in cultural activism and education, including as head of the Medu Art Ensemble;[3] she was also a published poet, writing under her married name, Baleka Kgositsile.

[9] In addition, the ANC Women's League was relaunched in August 1990, and Mbete served on the interim leadership corps that oversaw its re-establishment.

[13] In 1995, Mbete was appointed as chair of the ANC's parliamentary caucus and as a member of the Presidential Panel on the Truth and Reconciliation Commission.

[6] In May 1996,[14] she was promoted to deputise Frene Ginwala as Deputy Speaker of the National Assembly; she succeeded Bhadra Ranchod, who was appointed as an ambassador.

[15] During this period, in April 1997, it transpired that Mbete had received an improperly issued driver's license at a testing centre in Mpumalanga.

[5] The scandal led to a broader investigation into corruption into the Mpumalanga traffic department and to the dismissal of a provincial minister,[16] though Mbete was not charged with wrongdoing and maintained that she had been "caught up in a web of impropriety of which I was unaware".

In the aftermath of the 2004 general election, the ANC announced that it would nominate Mbete to replace Frene Ginwala as Speaker of the National Assembly.

[21]Mbete's term as Speaker coincided with the Travelgate scandal, which pertained to the abuse of parliamentary travel vouchers by politicians.

[24] Her efforts in this regard apparently led her into conflict with Zingile Dingani, the Secretary to Parliament, who sought an expanded mandate for his own office.

[24][25] In January 2006, Mbete chartered a jet, at a cost of R471,900 (around $60,000), to attend the inauguration of Ellen Johnson Sirleaf as President of Liberia.

[27] In the middle of her term as Speaker, Mbete was nominated to stand for an ANC leadership position during the party's 52nd National Conference, which was held in Polokwane in December 2007.

On 23 September, Mbete was announced by the SABC as the most likely candidate for Deputy President of South Africa following Phumzile Mlambo-Ngcuka's resignation from the position.

[33] In the next general election in April 2009, Mbete was re-elected to her parliamentary seat but, somewhat dramatically, declined to be sworn in as a Member of Parliament on 6 May, despite being present at the inauguration.

During the assembly's first sitting on 21 May 2014, she easily defeated the opposition candidate, receiving 260 votes compared to the 88 cast for Nosimo Balindlela of the Democratic Alliance.

[38] On 10 September 2014, five opposition parties, including the Democratic Alliance and Economic Freedom Fighters, stated that they planned to submit a motion of no confidence in Mbete, and claimed that she could not simultaneously serve as chairwoman of the ANC and as Speaker of the National Assembly.

[49][50] The ANC Women's League endorsed another candidate – Nkosazana Dlamini-Zuma – and Mbete was not viewed as a frontrunner, but she continued to campaign, under the banner #BM17, until the conference was held in December 2017.

[57] When the election was held in May, she was re-elected to her parliamentary seat, but, on 20 May, the ANC announced that it would nominate Thandi Modise, the outgoing head of the National Council of Provinces, to succeed Mbete as Speaker.

She and provincial secretary of the ANC in the Northern Cape Dr K M Seimelo are shareholders in Dyambu Holdings,[64] which is involved in building the massive Gautrain public transport project in the province of Gauteng.