She was elected to the Senate in 1987 and in Government held a number of executive positions including Parliamentary Secretary to the Minister for Immigration and the Minister for Foreign Affairs. In 2001, she was appointed to Cabinet as Minister for Health and Ageing and then in October 2003 Minister for Family and Community Services and Minister Assisting the Prime Minister for Women’s Issues.  She retired from the Cabinet in 2006 and from the Senate in June 2008.

In 2002 when Minister for Health she took legislation through the Senate on behalf of the Government which permitted within very strict parameters the creation of stem cell lines from donated embryos excess to IVF requirements.  In 2006, she developed a private member’s bill which passed into law in December of that year, to extend existing legislation permitting research using somatic cell nuclear transfer.

She was a member of Monash University Council for twenty years and has been a member of Guides Australia since she was 10 and a Life Member since 2002. She joined Interplast Australia and New Zealand as a Director and Board Member in 2006, was appointed Vice-President in 2009 and retired at the end of her term in 2015.  In September 2008 she was appointed Vice Chancellor’s Professorial Fellow at Monash University until 2015 and in 2016 was appointed a Professorial Fellow in the Monash Faculty of Medicine. She served on the National Mental Health Commission (2014-2016) and the Victorian Responsible Gambling Foundation (2014-2016). In 2016 she was appointed, for a 5 year term, as the Age Discrimination Commissioner at Australian Human Rights Commission.  In 2009 she was appointed a Director of the Brockhoff Foundation.  She is also Patron of the Australian Boys Choir.

Dr Patterson served on the ARMI Board from to 2009–2019 and became an Ambassador in 2021.