Nerve growth factor (NGF) receptor-like immunoreactivity has been demonstrated in the normal human adult spinal cord using the monoclonal antibody ME20.4. Intense immunoreactivity was associated with fibres and terminals in the substantia gelatinosa. In lamina IX the neuropil demonstrated punctate staining, the motor neurons themselves being negative. At thoracic levels occasional neurons of the intermediolateral column cell group were NGF receptor positive. Fine axonal and punctate terminal reactivity was observed in the gracile fasciculus, corresponding to axons in transverse section. Similar, though slightly less dense immunoreactivity was observed in the cuneate fasciculus. The demonstration of NGF receptor immunoreactivity may provide a useful marker of sensory innervation in the human spinal cord.