The authors intend to evaluate the results obtained from a pharmaco-economic project included in the 1999 and 2000 budgets. The objectives of the study are: 1) to establish whether there has been a saving in expenses for antibiotic therapy (T.A.) during the first half-year of 1999 and during the first half-year of 2000 and to ascertain the reasons for any positive result; 2) to evaluate the average hospital stay in the first half-year of 2000 and to observe how many times patients were been discharged early with shift therapy. Of the 286 patients (1999) and 309 (2000) considered, we focused attention on 187 (1999) and 190 patients (2000) who were treated with antibiotic therapy. A substantial cost saving was found in antibiotic use (-31%) in the first half-year of 2000 due to the early discharge and the continuation of home therapy for a fair number of patients and due to increased attention in the choice of medicine for less serious diseases. The second objective was not achieved with the reduction of average hospital stay even if the average length of antibiotic therapies (D.M.T.) fell from 13.1 days at 1st September to 9.8 days in the first half-year of 2000 (P:NS). These results suggest that projects designed to achieve financial savings and improvements require more cooperation between clinical U.O. and services that enable hospital stay to be shortened.