Auditory brainstem response (ABR) results with 82 severely developmentally delayed infants and children suspected of being both deaf and blind are reported. Of the 79 children on whom acceptable ABR data were obtained, 34 or 43.0% had ABR thresholds in the normal-hearing range; 16 or 20.3% in the mild-to-moderate loss range; and 3 or 3.8% in the severe loss category. Twenty-six or 32.9% produced no ABR to clicks at a maximum intensity of 90 dB HL. On the basis of established audiological and neurological diagnostic criteria, 3 children showed neurological abnormality by ABR. We conclude that the hearing status of a high percentage of otherwise untestable children can be determined by ABR, that a significant number of infants and children who appear deaf are in fact not hearing impaired, and that the occurrence of brainstem neuropathology in this population is limited.