As highlighted by previous research, prefrontal cortex is involved in the comprehension of idiomatic expression. It is here hypothesized that schizophrenic people, who show prefrontal structural changes and deficits in the dysexecutive behavior, will exhibit impaired idiom comprehension, and impaired performance on executive task, due to dysexecutive deficits. 45 schizophrenic patients and 45 control subjects were tested by means of a sentence-to-picture-matching task. The participants were presented 124 written sentences -62 literal, 62 idiomatic- with a picture below each sentence. If the picture represented or not the meaning of the sentence, they had to press one of the two response keys. Reaction time and answer accuracy were measured. The performance of the Schizophrenic subjects was significantly impaired in both types of idiomatic sentences, and particularly poor with ambiguous idioms. However, the ability to recognize false literal sentences was preserved and generally better than with idioms.