Hereditary high phosphatidylcholine hemolytic anemia (HHPCHA) is a hematological disorder characterized by chronic hemolytic anemia with a dominant pattern of inheritance. The affected members show increased numbers of target cells and/or stomatocytes in peripheral blood smears, have reduced erythrocyte osmotic fragility, increased autohemolysis as well as markedly increased erythrocyte membrane Na+, K(+)-ATPase activity. Erythrocyte membrane phosphatidylcholine is increased but plasma levels of this phospholipid are normal. Only 10 families affected with this disorder have been described in the literature. We are reporting a new family with HHPCHA in which there are two affected and four presumed affected members. In addition to anomalies commonly reported in HHPCHA, we found alterations in erythrocyte membrane acetylcholinesterase kinetics (low Vmax), reduced erythrocyte superoxide dismutase activity and increased susceptibility of erythrocytes to glutathione depletion on in vitro exposure to hydrogen peroxide. The pathogenesis and clinical features of previously reported cases of HHPCHA are also discussed.