In 1695, Jan Teofil Plater and his wife Aleksandra founded a hospital for six impoverished nobles in Vilnius. Situated near the newly built church of the Ascension and the convent of the Congregation of Mission in the Subocz suburb beyond the city walls, this hospital was the first and, until the end of the eighteenth century, the only charitable institution providing care for individuals of particular social status. The article, based on the hospital’s registry book and other sources, examines the quantitative, as well as qualitative characteristics of the institution’s clientele, such as its fluctuations in size, its social composition, and the causes of its inmates’ impoverishment. The research revealed that, despite the demand for care, the overseers managed to maintain a stable number of inmates, rarely admitting more than one or two persons every year, and thus ensuring a steady operation of the hospital (see table 1). However, in contrast with other charitable institutions in Vilnius, the clientele of the Congregation of Mission hospital changed frequently because of expulsions (39.6 percent of all cases) and inmates leaving the hospital on their own initiative (20.1 percent) already in the first year of their stay. The mortality of inmates (27.8 percent) affected the size and turnover of the clientele to a much lesser extent than observed in other hospitals. Although there are no reliable data on the inmates’ age and health, such statistics show that they probably were younger and healthier than the clients of other charitable institutions in Vilnius. Moreover, the Congregation of Mission hospital’s inmates differed from the clients of other institutions in respect of social composition. Impoverished petty nobles, originating mainly from the districts of Lida and Oszmiana, constituted the majority (56.25 percent) of the hospital’s inmates whose social status is noted in the registry book (62.5 percent). The nobles became clients of the Congregation of Mission hospital either because of old age, disability, as well as other accidental causes, or because of increased social vulnerability outside mutual aid networks, comprised of family members, kin or neighbours. The article argues that the foundation of a hospital designated to provide care primarily for impoverished nobles shows that the poverty of nobles was recognized by contemporaries as a social problem that should be tackled. Keywords: poverty, charity, hospital, the Congregation of Mission, Vilnius, nobles, eighteenth century.