This article draws on a collection of petitions by Palestinian Arabs and Jews to explore how families negotiated the admission of mentally ill relatives into government mental institutions under the British mandate between 1930 and 1948. In contrast to the conclusions of the existing literature, which focuses largely on the development of parallel Jewish institutions as establishing the foundations of the Israeli health system, these petitions reveal that the trajectories of both Arab and Jewish mentally ill were complex, traversing domestic, private, and government contexts in highly contingent ways. The second part of this article examines the petitions themselves as dense moments of engagement by Palestinian Arabs and Jews with the British mandate, in which the anxieties and priorities of the mandate were strategically re-deployed in order to secure admission into chronically underfunded and overcrowded institutions. Petitioners also sought to mobilize other actors, often within the state itself, as intercessors, a strategy which attempted to thread together state and society in a meaningful and advantageous way at a time when both seemed to be unravelling. Taken together, these pathways and petitions foreground the space of interaction between the British mandate and its subjects, thereby offering new perspectives on both.