The stimulus and response generalization effects of training wh-interrogative production were examined in 4 agrammatic Broca's aphasic subjects using a multiple baseline design across behaviors and subjects. Throughout treatment, response generalization to untrained questions and stimulus generalization to several nontraining conditions were assessed. Variable response generalization to untrained exemplars of trained wh-interrogative forms and little generalization to grammatically different wh constructions occurred. Stimulus generalization to only one of three conditions was noted. However, generalization treatment involving sequential modification of training across conditions was found to be effective in facilitating generalization to an additional stimulus condition for 2 of the 4 subjects.