Two further cases of human neurolymphomatosis are reported, and clinical, histopathologic and nosologic features of the affection reviewed with respect to findings in these 2 patients and in 7 other reported cases. Clinical manifestations are those of a flaccid ascending paralysis, associated in most cases with an asymmetrical abolition of tendon reflexes, violent muscular pains and sphincter disturbances, frequently preceded by a regressive cranial nerve palsy. Pathology shows infiltration of the peripheral nervous system (nerves, roots, and spinal ganglia) by lymphoid cells, sometimes associated with central nervous system (cord and brain) infiltrates in severe advanced cases. Involved nerves are increased in size. The disease could be a viral polyradiculoneuritis due to the virus of Marek's disease. Arguments in favor of this hypothesis include: the onset of the affection in subjects working in poultry farms under poor hygienic condition: the fact that clinical and histologic findings are similar to those in Marek's disease and the failure, after careful examination, to detect any malignant blood disorder or lymphoma in one of the cases studied.