Marisa Matias has been a Member of the European Parliament since 2009 and Vice-President of the Parliamentary Group A ESQUERDA.

She is a Member and Coordinator of the ITRE Committee (Industry, Research and Energy), and in that capacity she was rapporteur for the EIT (European Institute of Technology) and shadow rapporteur for the Horizon Europa Program and many other dossiers related to the digital agenda, cybersecurity, supercomputing and Roaming. He is currently a member of the European Parliament Contact Group for the COVID-19 Vaccine.

She is also a member of the AFET (External Affairs) and DROI (Human Rights) committees and a member of the ANIT Inquiry Committee (Protection of Animals during Transport).

In previous legislatures, she was a member of the ECON Committee (Economic and Monetary Affairs) and was its coordinator.

She was also a member of the Special Committees for Tax Regulation and other measures of a similar nature or effect, she was a member of the TAXE2 committee, where he was Vice-President and was also a member of the Special Committee on Financial Crimes, Evasion and Tax Elimination.

She was also a member of the ENVI Committee (Environment and Public Health) in which she was rapporteur for the European directive on counterfeit medicines.

As President of the Parliament for relations with the Maxreek countries (Lebanon, Syria, Jordan and Egypt) he took part and chaired several parliamentary negotiations, coordinating negotiation processes with corresponding national parliaments with particular concern for the situation of refugees in the region.

During 2010-2016 he was Vice President of the European Left Party.

Marisa Matias was the EU's chief observer for the elections in Honduras (2017) and Sri Lanka (2019).

In 2016 Marisa Matias was a candidate for the presidential elections in Portugal and in 2021 she was again a candidate for the Portuguese presidential elections.

Her areas of interest and work include human rights, environment and climate change, public health, science, digital, research, democracy, citizenship and women's rights.
Marisa Matias has been a strong voice in the situation of informal caregivers, both nationally and in Europe.

Marisa Matias has a PhD in Sociology from the Faculty of Economics of the University of Coimbra and was a researcher at the Center for Social Studies.