She was a Chama Cha Mapinduzi (CCM) Member of the National Assembly for Muleba South constituency during 2010 to 2020 and served as the Minister of Lands, Housing and Human Settlement Developments from 2010 to 2014.

Tibaijuka was elected by the General Assembly to her first four-year term as head of the new agency in July 2002 and was given the rank of under-secretary-general, as the first African woman to reach this level within the UN system.

[4] In June 2005, the Secretary-General appointed Tibaijuka as his Special Envoy on Human Settlements Issues in Zimbabwe, with the directive to study the impact of the Zimbabwean government's campaign to evict informal traders and people deemed to be squatting illegally in certain areas, known as Operation Murambatsvina.

[6] Tibaijuka concluded her report saying that “while purporting to target illegal dwellings and structures and to clamp down on alleged illicit activities, [the operation] was carried out in an indiscriminate and unjustified manner, with indifference to human suffering”.

In December 2014, President of the United Republic of Tanzania Jakaya Kikwete sacked Tibaijuka from a post of Minister for Lands, Housing and Human Settlement Development over her alleged involvement in the US$250 million Tegeta escrow account scandal.

Kikwete said he had asked Tibaijuka to "leave room for a new appointee," after she had not shown "due diligence" when receiving US$1 million from James Rugemalira of VIP Engineering and Marketing (VIPEM) linked to the scandal.