The authors examined psychotic patients with schizophrenia, major depression, and bipolar disorder; "normal" participants; and 1st-degree relatives of patients with schizophrenia on an antisaccade task in which participants were instructed to move their eyes in the opposite direction of a target that moved unpredictably and abruptly either to the left or right of central fixation. Patients with schizophrenia were found to make significantly more errors than their relatives, and the latter made more errors than the controls. The poor performance of the relatives could not be attributed to their having a psychiatric disorder. Comparison of the 3 patient groups indicated that antisaccade deficits were more pronounced in schizophrenia and bipolar disorder.