The Copenhagen longitudinal high-risk study of offspring of 129 schizophrenic mothers commenced in 1962. At that time, the mothers were diagnosed according to contemporary Danish criteria. We have re-examined all of the hospital records of these mothers: 108 (84%) fulfil present-day DSM-III criteria for schizophrenia and 95 (74%) were diagnosed as paranoid schizophrenic according to ICD-8 criteria. In a follow-up at mean age 24, the offspring of the paranoid schizophrenic mothers were themselves found to be less frequently schizophrenic (5%) than were the offspring of non-paranoid schizophrenic mothers (29%).