This paper examines whether neuropsychological profiles of youth with early onset psychotic disorders predicted diagnostic or clinical status. Youth with schizophrenia (n=27), bipolar disorder (n=22), and psychosis NOS (n=20) were included. Subjects received an extensive neuropsychological evaluation, including measures of general cognition, attention, memory, and executive functioning. Medication status was not controlled. No statistically significant neurocognitive differences across diagnostic groups were found. Compared to standardized norms, youth with schizophrenia demonstrated deficits in general cognition, verbal learning, recall, sustained effort, and social knowledge. Subjects with bipolar disorder and psychosis NOS exhibited deficits on measures of verbal learning, recall, and sustained effort similar to those of youth with schizophrenia. Neurocognitive deficits in memory and attention appeared to be common among youth with psychotic illnesses, regardless of diagnosis. Those with schizophrenia may have greater global cognitive deficits and problems with social knowledge. Across diagnoses, subjects demonstrated relative strengths on tests that provided them with immediate feedback, and performed most poorly on tests requiring delayed recall.