All hospital records, interviews, and notes are reviewed on a group of 52 chronic hebephrenic/catatonic schizophrenics who were institutionalized before the era of antipsychotic medications. The authors catalog the presence or absence of individual symptoms of schizophrenia on a year by year basis over a span of 25 years and present this data in a series of bar graphs. Symptoms such as avolition, impaired social interaction, and flat affect become more frequent over the 25 years of follow-up. Hallucinations and delusions become less frequent. Eighteen of the patients are noted to have had a DSM-III personality disorder premorbidly and eight of these are characterized as schizoid personality disorder. Level of insight is found to be poor at the onset of schizophrenia and deteriorates further over the next 5 years. Although the study design contains a sampling bias in favor of chronically institutionalized cases, several lines of evidence suggest that the trends reported here are not artifacts of institutionalization but are due to schizophrenia.