This paper considers data on hysterical neurosis, conversion type from the Monroe County (New York) Cumulative Psychiatric Case Register, from the Psychiatric Case Register in Iceland, and from a psychiatric consultation service in a university teaching general hospital in Monroe County (New York) during the period 1960 to 1969. The rate of hysterical neurosis, conversion type in Monroe County during this period was 22 per 100,000 per year, whereas in Iceland it was 11 per 100,000 per year. It was highest for women, non-whites and those of low social economic status. The rate of hysterical neurosis, conversion type and "probable" hysterical neurosis, conversion type combined among patients seen in psychiatric consultation was 4.5%. The most often noted diagnostic criteria were inconsistency with somatic process and precipitation of symptoms by psychological stress. Most patients had more than one conversion symptom at the same time. Pain was the most common symptom. The majority of patients had an accompanying organic or functional illness.