OBJECTIVE The aim of the present epidemiological study is to gather information on the state of oral health in both hospitalized and non-hospitalized patients in Milan, in order to evaluate the prevalence of periodontal disease and to carry out a comparison between the 2 groups. METHODS The study involved 364 patients (111 males, 253 females) aged between 65 and 104, subdivided into 2 groups: 1) the 1(st) group of 258 hospitalized patients; 2) the 2(nd) group consisted of 106 non-hospitalized patients. In order to carry out the examinations 5 orthodontic mirrors, traditional orthodontic O.M.S. probes, and a source of white light were utilized. The epidemiological parameters utilized, according to O.M.S. criteria, were D.M.F.T. and C.P.I.T.N. RESULTS The results obtained by the dental examinations were registered by means of the ''Scheda di Valutazione O.M.S'' (O.M.S. Evaluation Report). Hospitalized patients D.M.F.T. 24,99, C.P.I.T.N. 1,40; non-hospitalized patients D.M.F.T. 19,82, C.P.I.T.N. 1,78. 42.3% of patients proved to be edentulous (49.6% hospitalized patients; 28.3% non-hospitalized patients). Of these, 45% wore dentures. CONCLUSIONS The value of D.M.F.T. in elderly hospitalized patients was higher than in non-hospitalized patients; decay is thus prevalent in hospitalized patients. If we observe the values of C.P.I.T.N., a worrisome datum emerges: neither of the 2 groups are aware of correct oral hygiene techniques. Therefore, the clinical results derived from our study highlight the need to create a specific oral health program, directed at the elderly.