The heterogeneity of schizophrenia constitutes an impediment in the identification of reliable biological markers of the illness and aetiological factors. The two syndrome concept of the illness has proved a powerful stimulus in this endeavour. There is however evidence now to regard this construct as inadequate and in need of refinement. Using a sample of young patients with early onset of illness who fulfilled the Research Diagnostic Criteria for schizophrenia, we have shown that three rather than two dimensions better describe the pathology of the illness. The results of factor analysis showed these syndromes, termed disorganization, positive, and negative syndromes, to account for 65% of the total variance of the psychopathology of the disorder. The negative syndrome was associated with disturbed pre-morbid functioning while the disorganization syndrome bore significant association with early onset of illness, poorer socio-educational attainment, and impairment on neuropsychological tests, especially those designed to evaluate frontal lobe functioning. The positive syndrome was not associated with any of the assessed variables. These results provide strong support for the validity of the three-syndrome construct even among a sample of non-institutionalized patients.