Seventeen spontaneous speech measures and scores on a naming test, employed to characterize the expressive performance of 121 aphasics, were subjected to a factor analysis. Five factors were obtained: (1) Syntactic ability, (2) Phonological paraphasia, (3) Neologistic paraphasia, (4) Articulatory impairment, and (5) Vocabulary. Relationships of the factors to naming error types were examined in order to elucidate the nature of some of the factors. Also, the relationships of the expressive factors to auditory comprehension tests were explored, such an exploration being relevant to the issue of the overlap between expressive and receptive functions.