The nailfold capillary pattern was studied in 152 subjects: 60 normal, 50 familial, and 42 nonfamilial schizophrenic patients. Significant correlation exists between family history and visibility of the subpapillary plexus in the nailfold. The duration of illness is greater and there are more older patients in the familial group. High plexus rating is not related to chronological age, sex, or duration of illness. The incidence of above normal blood pressure is essentially the same in high plexus-low plexus groups. It is concluded that there is a familial group of schizophrenic patients constitutionally different from the other schizophrenics; the combination of family history and plexus rating as criteria make it possible to select a homogeneous group of patients for further study in schizophrenia.