The concept of schizophrenic reaction was introduced in 1920 by Popper for single schizophrenic manifestations of short duration and full recovery, occurring after a traumatic experience. Of the 29 probands with a primary diagnosis of schizophrenic reaction when recruited for study by Rohr (report published 1961), 28 were reevaluated 20 years later. Nineteen subjects now had a clear-cut schizophrenic symptomatology (ICD 295); 16 with, and three without, remaining symptoms and/or relapse. The other nine were now diagnosed under nosologic categories other than ICD 295. Of these subjects, four were symptom free and had suffered no relapse. The study did not reveal criteria suggesting a distinguishable nosologic category 'schizophrenic reaction' with reference to a schizophrenic syndrome of acute or subacute onset after a brief traumatic event (without remaining symptoms and/or relapse). Such probands did not differ from the schizophrenic group in any of the following criteria: psychopathology, heredity data (diagnosis of relatives was undertaken without reference to the respective index cases), time of onset, duration of psychopathologic manifestation, length of hospitalization, period without remaining symptoms or relapse, and frequency and type of traumatic experiences. The two groups with schizophrenic symptomatology (ICD 295) are genetically characterized by the fact that their first-degree relatives had an incidence of schizophrenia of 8.3 +/- 2.6%. On the other hand, no certain cases of schizophrenia were found among such relatives of subjects in other diagnostic groups. The results do not support the concept of schizophrenic reaction.