Between 1924 and 1939, over 100 immigrants were deported from Western Australian mental hospitals. These deported ‘lunatics’ fell within the 3-year (and later 5-year) window between arrival and becoming ‘a charge on the state’. This meant that they could be deported by the Australian Commonwealth government under Section 8a of the amended Immigration Restriction Act. So who were these lunatic migrants? Were they already unwell and deliberately encouraged to migrate to Australia by unscrupulous foreign governments? Were they simply people for whom the pressures of life in an unfamiliar culture, in the middle of a global economic depression, became too much? By examining these deportees in more detail, and looking at factors such as their ethnic background and diagnosis, some underlying reasons as to why these individuals were targeted for deportation become apparent.