Sutkus's series People of Lithuania is considered one of his most important works. It is a continuing project begun in 1976 to document the changing life and people of Lithuania. Working at the time when Lithuania (as the Lithuanian SSR) was part of the Soviet Union, Sutkus focused on black and white portraits of ordinary people in their everyday life rather than the model citizens and workers promoted by Soviet propaganda. Sutkus had an opportunity to spend time with Jean-Paul Sartre and Simone de Beauvoir in 1965 when they visited Lithuania. One image, taken against the white sand of Nida, is highly regarded as capturing Sartre's ideas.