Background: The anterior cingulate cortex (ACC) is consistently implicated in the pathophysiology of schizophrenia, and our own work has identified morphological anomalies in the ACC of people with this disorder. Aims: To examine whether ACC morphological anomalies are present in a group at ultra-high risk of psychosis and whether such anomalies can be used to predict the subsequent development of a psychotic illness. Method: Magnetic resonance imaging of 75 healthy volunteers and 63 people at ultra-high risk of developing a psychotic disorder (all right-handed males) was used to examine ACC sulcal and gyral features. Results: Compared with the controls, significantly fewer people in the ultra-high risk group had a well-developed left paracingulate sulcus and significantly more had an interrupted left cingulate sulcus. There was no difference between those who did (n=21) and did not (n=42) subsequently develop a psychotic illness. Conclusions: Although ACC anomalies are present in young people considered to be at ultra-high risk of psychosis, they do not identify individuals who subsequently make the transition to psychosis.