In the two consecutive legislative elections of May and June 2012, she was elected a member of the Hellenic Parliament for the suburban Athens B constituency. In a television appearance on 7 June 2012, far-right Golden Dawn party's MP Ilias Kasidiaris threw a glass of water at Dourou, proceeding to physically assault Liana Kanelli after she objected to his behavior. The incident caused an uproar, both nationally and internationally, and was widely seen as a moment of revelation regarding Golden Dawn's violent agenda. Following the elections, Dourou was appointed to the Shadow Cabinet of Alexis Tsipras, where she was made responsible for foreign policy. In the beginning, Dourou had to cope with prejudices against female politicians, with a Kathimerini commentator railing that the "nice blonde" be rather "a qualified kindergarten teacher" than qualified on foreign policy issues. However, she fought her way through male dominance and sexism, defining Syriza's defence and foreign policy, as to be increasingly described her party's "rising star".
Governor of Attica
On 26 March 2014, well ahead of the local elections in May, she ceded her parliamentary seat to her party's first runner-upEleni Avlonitou in order to fully concentrate on campaigning for regional governor of Attica. For her all-in decision, she gained further respect, being referred to as the first member of parliament to do so. Running a door-to-door campaign on an electoral platform called "Power of Life", she challenged incumbent Giannis Sgouros who ran for the social-liberal "Social Values" party, and won the first round. Though in the decisive runoff ballot, Sgouros had the backing of both Nea Dimokratia and PASOK parties, Dourou defeated him with 50.83% of the popular vote. Ahead of Syriza's victory at the January 2015 legislative election, her election as regional governor was widely described as Syriza's biggest victory so far. In charge of a €575m annual budget, she immediately increased social welfare spending from €1.9m to €13.5m in order to establish food banks, health care for the uninsured. She also ordered tens of thousands disconnected from electricity to be reconnected. She was criticized by Minister of Administrative Reform Kyriakos Mitsotakis for supporting 19 mayors who refused to hand over municipal workers' files for evaluation.
Controversies
Dourou was heavily criticized for her decision to scrap four tenders for waste management plants. It was estimated that her decision lost 200 million of funding with ecological implications and a lack of capacity in the Attica waste management system. Deputy Development Minister Notis Mitarakis called on Dourou to "realize the difference between governing and protesting." He also argued that the Attica governor could not cancel the tenders on her own. Dourou is in favor of the separation of the church and state and took a non-religious oath when she was sworn in as governor, eliciting criticism from conservative and right-wing milieus.