Peripheral vascular complaints first raised the question of polycythemia vera in 16 of 26 patients with this disease. Manifestations suggestive of polycythemia vera included red or cyanotic fingers or toes with or without burning pain, notably when pulses were palpable; occasional erythromelalgia; thrombophlebitis without other known cause; and the occurrence of coronary or cerebral ischemia at an early age. In six of the 16 patients, elevated platelet counts were found in the presence of normal venous hematocrit readings. Three of these patients had significant leukocytosis. In these patients, and in the others without organic arterial lesions, lowering of the hematocrit reading or platelet count or both proved beneficial and usually curative. Severe secondary polycythemia may at times produce symptoms similar to those of polycythemia vera. Surgeons and dermatologists have special opportunities to identify polycythemia vera among their patients.