I. Mažeikienė has been working in the field of museology since 1995.During twenty years of intensive professional activity, she has accumulated extensive experience in preserving, researching, and disseminating art heritage, which is evidenced by her exhibitions, catalogues, insights and new interpretations of works. Every year, I. Mažeikienė adds to the treasure chest of Lithuanian culture with works from three areas: Vilnius art, Lithuanian diaspora and Western European art. Mažeikienė has been researching Vilnius art since her studies at the Vilnius Academy of Arts, publishing scientific articles on the subject, giving presentations at conferences, and since 2013 she has been running a continuous cycle of exhibitions "Vilnius Art of the 19th-20th Century", and publicising the Vilnius art held in various institutions or private collections. She is the publicity manager of the exhibits (the exhibition "Gods and People. The World of Ancient Myths and Legends" (2008), "The Most Beautiful Cities of Western Europe, Their Palaces and Parks" (2016-2017), etc.), and presents personalities of global significance and their works. She has curated exhibitions of Francis Goya's Caprichos, Antoine Watteau's legacy from the collections of the Louvre Museum, and Alfred Kubin's graphic art and drawings.
Since 2013, Mažeikienė has been the director of the Vytautas Kasiulis Art Museum. Together with Romualdas Budrys and Laima Bialopetravičienė, she has taken over the collection of works and archives donated to Lithuania by the artist's family, developed the concept of the exhibition, and shaped the main guidelines of the new museum. The museum runs a continuous programme of research on diaspora art, "Outcrops of Lithuanian Diaspora Art", which enriches the national art field with the significant creative legacy of Arbit Blatas, Alfonsas Dargis, Viktoras Petravičius, Antanas Mončius, Henrikas Šalkauskas and Eva Kubba.
