Dr Tshabalala-Msimang worked as Registrar, Obsterics and Gynaecology at Muhumbili Hospital in Dar es Salaam, Tanzania; a Medical Superintendent responsible for 10 satellite clinics at the Lobatse Hospital in Botswana; head of Health Training Programme for National Liberation Movements in the Organisation of African Unity / United Nations Development Programme at Morogoro in Tanzania from 1976 to 1979.
She also worked as a Deputy Secretary in charge of human resource development and deployment for the African National Congress (ANC), Department of Health, Tanzania/ Zambia from 1979 to 1990. She Convened the First International Conference on Health and apartheid under the auspices of World Health Organisation in 1980 and she held
several positions in the National Progressive Primary Health Care Network in Durban from 1991 to 1994.
She was a Co-ordinator of the ANC's Health Plan (Section on Women's Health) from 1991 to 1994; a Board member of the Mohammed Ghandi settlement Clinic Committee in Durban in 1990; and a Chairperson of the Natal Women Resource Centre Committee; a Member of the Africa and Middle East Regions Steering Committee of Parliamentarians for Population and Development from 1994.
She was also African Union (AU) goodwill Ambassador and Champion for Africa's Movement to improve Maternal Health and Promote Child Survival and Development in Africa, beyond 2015; and Coordinated establishment of the South African National AIDS Council in 2002.
She also Coordinated the development of the National Strategic Plan on HIV/AIDS and STs or TB plan on the Management Care and treatment of HIV/AIDS and STs from 2002 to 2005 and the review of Comprehensive plan of Management, Care Support and Treatment of HIV/AIDS and STs.
Dr Tshabalala-Msimang Coordinated Operational Plan for the comprehensive HIV and AIDS Management, Treatement Care and Support Adopted November 2003 and implemented April 2004. She also coordinated the Review of NSP 2000-2005 conducted in July/August 2006.
She Coordinated the Review of SANAC 2002 and subsequent restructuring April 2006; Coordinated the Midterm review of comprehensive plan conducted in 2006/2007 and Coordinated the development of the South African Traditional Medicine Policy.
She was a Convener of National Youth Indaba on Health from 2004. She was a member of the Board of the Global Fund to fight HIV and AIDS, Malaria and Tuberculosis representing the Eastern and Southern Africa Constituency. She was also a Chair of Non-Aligned Movement of Health Ministers and Chairperson of SADC Health Sectoral Committee of Ministers.
She was also a Chairperson of the World Health Organisation (WHO) Afro Regional Commitee of Health Ministers; Vice-President of the 57th World Health Assembly; a CAMH3 Chairperson of the AU Ministers of Health; member of African National Congress (ANC) National Executive Committee (NEC) and member of ANC Women's League National Executive Committee.