A RECENT analysis by Russell and Conley ¹ of so-called benign polycythemia, or Gaisböck's syndrome, showed a high frequency of stocky body build, plethoric appearance, anxiety tension state, hypertension, and vascular disease; genetic factors were thought to play a significant role in the pathogenesis. Their report, together with those of Lawrence, Berlin, and Huff ² and Kaung and Peterson,³ may leave the impression that benign polycythemia is a nosological entity. It is the purpose of this essay to point out that benign polycythemia is neither a disease sui generis nor a syndrome demanding nosological recognition, and to support Wintrobe⁴ that there is probably no such entity. The condition as described was not benign and not polycythemia; its apparent association with stocky body build, hypertension, and vascular disease was probably influenced by the mode of case selection, and no convincing data were given to support the contention of abnormally high