Four patients with organic neurological disease (multiple sclerosis) had additional major hysterical disability. Patients with unequivocal organic disease often have coexistent psychological disturbances. The preexisting personality, nature of the organic disease and its disability, and the psychosocial setting interact and create an illness whose components are difficult to separate. In some patients there are definite secondary gains from an illness. The combination of hysteria and multiple sclerosis serves as a model for the coexistence of organic and psychological disorders; it serves as an example of the general questions of how the sick deal with their infirmities and how the physician comprehensively deals with illness.