Eight-hundred-and-fifty patients, i.e., 98 percent of the whole population of detainees in psychiatric hospitals in Poland in 1994, were studied. The aim was to describe this group. It was found that the group was less numerous than in the sixties and seventies and that it was relatively smaller than corresponding groups in such European countries as Germany and the United Kingdom. In comparison with other psychiatric patients, the group under study revealed considerable intensity of negative clinical and pathological features (among others – a very high proportion of gravely disturbed persons, repeatedly hospitalized before, with long detention periods). They also manifested significant deficiency of social adaptation (loneliness, lack of education, professional passivity, violation of basic legal norms).