She was one of the persons involved in preparing the controversial contract of co-operation between the Estonian Centre Party and Russian 'party of the power' United Russia in December 2004.

In late September 2014, she and fellow parliamentarian Marietta de Pourbaix-Lundin of Sweden assessed the reform agenda initiated by President Petro Poroshenko of Ukraine, reviewed the state of the armed insurgency in the east of Ukraine, and evaluated ethnic tensions in Odesa following the fire of 2 May.

[7] Mailis Reps was heavily criticised after her official visit to the Mari-El Republic, a federal subject of Russia in August 2005.

While several European (including Estonian) politicians have drawn attention to the discrimination of Mari people in this republic and issued statements on the topic, Mailis Reps spoke very positively about the current state of native inhabitants, their culture and education in her interview to Russian television.

After marrying a Latvian lawyer Agris Repšs she started to use a simplified version of her husband's surname (Reps).