The symptom dimensions of childhood-onset schizophrenia (COS) are described by focussing on the clinical features of 44 patients at onset of illness during the first episode and at follow-up investigation 42 years after onset. All subjects were re-diagnosed according to DSM IV. The symptomatology was evaluated with the Positive and Negative Symptom Scale (PANSS) at onset and at follow-up. Two principal component factor analyses with varimax-rotation were applied to the complete items set of the PANSS. The frequencies of positive, negative, and global symptoms were compared longitudinally in an ANOVA-repeated measures design. The factor analysis revealed 5 orthogonal symptom dimensions (factors) at onset of psychosis: Cognition, social withdrawal, antisocial behaviour, excitement, and reality distortion. At follow-up a five-factor solution was found, too, but different dimensions emerged: a positive, negative, excitement, cognitive, and anxiety/depression component which fits to the 5-factor model of White et al. (1997). The first psychotic episode of EOS is accompanied with more unspecific symptoms such as social withdrawal and antisocial behavior. In the later stages of (COS) the structure of symptom dimensions changes to that known from adult-onset schizophrenia (AOS). The results indicate that COS and AOS are comparable nosological entities and that more than 3 dimensions are required to describe the relevant clinical symptom structure. Positive and global symptoms decreased significantly during the course of illness. The frequencies of negative symptoms did not change which demonstrates their disabling impact.