Denmark was a pioneer country in establishing island institutions for people with intellectual disabilities. The main figure behind these initiatives was disability doctor Christian Keller, who was instrumental in the Danish eugenic movement. In 1923, he founded the first institution for “morally mental deficient” or “antisocial” women on the island Sprogø. More than five hundred women were interned on Sprogø during its time of operation. Keller’s initiative attracted wide public attention, and his ideas were highly praised by the press. By the late 1950s, however, views on the proper means and ends had radically changed, the island institution was no longer considered an appropriate solution, and it was terminated in 1961. In popular culture today, Sprogø is often portrayed as equivalent to a prison. However, archival sources of the time and interviews with former inmates from Sprogø provide a more complex picture. By examining patient records, oral history interviews, and other primary sources, we discuss the issue of exclusion and the patients’ perspective and compare these with recent accounts on the history of the island institution. We argue that the women on Sprogø not only were victims of disciplinary exclusion but also had a social life and experienced a certain amount of freedom on the island which was rarely the case on the mainland.