Mašiotas also participated in cultural and political life in Lithuania. In 1902, he participated in the founding meeting of the Lithuanian Democratic Party and was elected to its central committee. During the Russian Revolution of 1905, he attended the Great Seimas of Vilnius. In 1905, Mašiotas became a member of the 20-member committee tasked with organizing the Lithuanian Scientific Society which was officially established in April 1907. He contributed his ethnographic photographs to the society. Some of his photos were added to the Lithuanian exhibition at the International Paris Exposition in 1900.