A long-term follow-up study with a mean duration of 20.2 years was performed in 5-year periods for 280 male schizophrenic patients discharged 1946-1950. To avoid a heterogeneous evaluation of the prognosis the author combined the outcome variables 'symptomatology', 'working ability' and 'social integration' as 'overall prognostic index'. Thus the final results show that prognosis is favorable in one-half of the patients (50.7%), relatively favorable in less than one-fourth (21.8%) and unfavorable in about one-fourth of the cases (27.5%). The author stated further that the prognosis is correlated with less clinical and more socially determined factors. In most of the cases favorable and unfavorable prognostic variables are both simultaneously presented, which does not allow the prospective prediction of individual prognosis in schizophrenia.