Impairments in using eye gaze to establish joint attention and to comprehend the mental states and intentions of other people are striking features of autism. Here, using event-related functional MRI (fMRI), we show that in autism, brain regions involved in gaze processing, i ncluding the superior temporal sulcus (STS) region, are not sensitive to intenti ons conveyed by observed gaze shifts. On congruent trials, subjects watched as a virtual actor looked towards a checkerboard that appeared in her visual field, confirming the subject’s expectation regarding what the actor ‘ought to do’in this context. On incongruent trials, she looked towards empty space, violating the subject’s expectation. Consistent with a prior report from our laboratory t hat used this task in neurologically normal subjects, ‘errors’(incongruent tri als) evoked more activity in the STS and other brain regions linked to social co gnition, indicating a strong effect of intention in typically developing subject s (n=9). The same brain regions were activated during observation of gaze shifts in subjects with autism (n=10), but did not differentiate congruent and incongr uent trials, indicating that activity in these regions was not modulated by the context of the perceived gaze shift. These results demonstrate a difference in t he response of brain regions underlying eye gaze processing in autism. We conclu de that lack of modulation of the STS region by gaze shifts that convey differen t intentions contributes to the eye gaze processing deficits associated with aut ism. Impairments in using eye gaze to establish joint attention and to comprehend the mental states and intentions of other people are striking features of autism. Here, using event-related functional MRI (fMRI), we show that in autism, brain regions involved in gaze processing On congruent trials, subjects watched as a virtual actor looking towards a checkerboard that appear in her visual field, confirming the subject’s expectation regarding what the actor ’ought to do’in this context. On incongruent trials, she looked towards empty space, violating the subject’s expectation. Consistent with a prior report from our laboratory t hat used this task in neurologically normal subjects,’ errors’ (incongruent tri als) evoked more activity in the STS and other brain regions linked to social co gnition, indicating a strong effect of intention in typically developing subj The same brain regions were activated during observation of gaze shifts in subjects with autism (n = 10), but did not differentiate congruent and incongr uent trials, indicating that the activity in these regions was not modulated by the context of the perceived gaze shift. These results demonstrate a difference in t he response of brain regions underlying eye gaze processing in autism. We conclu de that lack of modulation of the STS region by gaze shifts that convey differen t intentions contributes to eye eye gaze processing deficits associated with aut ism.