The purpose of the study was to ascertain if Broca's aphasics have a comprehension defect which is dependent on syntactic relationships, to ascertain how this comprehension defect, if present, is different from that seen in Wernicke's and conduction aphasias. Twenty-six aphasic patients (nine Broca's, eight conduction, nine Wernicke's) and eight controls were given a test which helped differentiate comprehension errors caused by syntactic incompetence from those caused by lexical incompetence. Wernicke's aphasics made significantly more lexical errors than each of the other groups. There were no significant differences between the lexical errors made by the other groups (Broca's, conduction, and control. There were no significant differences between Broca's and conduction aphasics, however, both these groups made more syntactic errors than. the controls. © 1976, Masson Italia Periodici s.r.l. Milano. All rights reserved.