According to clinical experience a frequent consequence of head injury is an impairment of auditory attention. We investigated the possibility that patients with either closed head injuries (CHI), or cerebrovascular accidents (CVA) of the right hemisphere, would be impaired by comparison to healthy subjects on an objective test of auditory attention. We used an experimental paradigm that consisted of four subtests which comprised strings of auditory digits heard either diotically or dichotically, at either fast or slow presentation rates, respectively. Omission and commission errors were scored for each subtest and combined by an index of errors. The results showed that CHI patients were significantly impaired initially by the fast stimulus presentation conditions, whereas CVA patients made significantly more errors on the dichotic subtests independent of the speed of presentation. It is proposed that the observed selective attention deficits of these patients were due to differential disruptions of an interactive cortical network incorporating prefrontal, anterior cingulate, and temporoparietal structures of the right hemisphere. Statistically significant correlations between the error index scores and subjectively perceived attention deficits suggested that the auditory attention task measured clinically relevant aspects of attention.