Neonatal polycythemia and erythropheresisNinety one newborn babies with polycythemia that went on exchange transfusion with plasma were studied retrospectively over a 30 months period: 57.1% were adequate for gestacional age newborn babies. Plethoric appearance, tremors and cyanosis were the most frequent findings. Small for gestational age, big for festational age and Down Syndrome were important associated facts in this group, nevertheless in 31.9% no related facts were present. Hypertension during pregnancy was the most frequent maternal disease in these patients. No complications were detected in 87.9%of the 91 newborn babies that went on exchange transfusions while 6-6 %had onphalitis, 2.2%sepsis, 2.2%necroti/,ing enterocolitis and 1.1 meningitis. (Key words: neonatal polycytemia, erythropheresis).La policitemia neonatal es potencialmente productora de complicaciones serias en el sistema nervioso central, corazon, pulmones, riflones e intestine, secundarias a alteraciones de la microcirculacion.El tratamiento de los recien nacidos con policitemia e hiperviscosidad es relativamente simple, pero controvertido en relacion al criterio de la seleccion de los casos segim el hematocrito y los sintomas. Existe consenso en que se puede realizar exanguineotransfusiones parciales para reemplazar la sangre por soluciones cristaloides o coloides. Se han usado soluciones salinas, de albuminas y plasma, siendo el recambio con