Objective: To identify changes of prescription patterns in long term psychiatric inpatients in 1995 and 2009. Material and Methods: Cross sectional comparative study of two one-day-census, (06/15/1995 and 12/14/2009) at the Hospital Neuropsiquiátrico Alejandro Korn, Argentina. Records of prescribed psychotropic agents to all patients in long stay wards were examined. Results: The number of hospitalized patients decreased 33% from 1995 (n=1048) to 2009 (n=698), with increases in male gender (44% a 57%) and hospitalizations lasting more than 20 years (29% a 40%). Schizophrenia remained as the most prevalent diagnosis followed by learning disabilities/mental retardation (45% and 27% in 1995, respectively, 44% and 33% in 2009). The average antipsychotic dosis in schizophrenia was almost the same, the equivalent of around 760 mg of chlorpromazine. Patients on antipsychotic doses above an equ...