The cerebrospinal fluid monoamine metabolites, homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5HIAA), were compared with ventricle-brain ratios (VBRs) in a group of adolescent inpatients who were divided into psychotic and nonpsychotic groups. HVA, 5HIAA, and VBR did not differ significantly between the two groups. There were no significant relationships between these variables in the nonpsychotic group. Psychotic adolescents, however, displayed significant negative correlations between VBR and HVA, and between VBR and 5HIAA. The relationship between VBR and monoamine metabolites appears to occur in psychoses other than schizophrenia, is present early in the course of illness, and probably does not represent a dilutional effect.