Schizophrenics, manics, depressives and normal subjects (15 in each group) were tested for their ability to understand and express the prosodic quality of speech. Sentences in which one word was stressed (stress prosody comprehension) or in which a particular emotion was conveyed (emotional prosody comprehension) were taped and played to subjects to test their comprehension. Subjects were then asked to read out a list of sentences either stressing a nominated word (stress prosody expression) or conveying a nominated emotion (emotional prosody expression), and their efforts were rated by a panel of normal raters. The main results were 1) that schizophrenics were significantly inferior to the normal group, but equivalent to manics and depressives on emotional prosody comprehension; 2) schizophrenics were significantly inferior to all other groups on emotional prosody expression; and 3) all four groups were equivalently proficient on stress prosody comprehension and expression. The results are interpreted as lending support for the idea that there is an underlying right hemisphere dysfunction in schizophrenia.