Dehydrated hereditary stomatocytosis is a haemolytic anaemia with an underlying impairment of monovalent cation transport. It is sometimes associated with pseudohyperkalaemia (e.g. an increase of kalaemia when blood is left at room temperature) or with perinatal ascites. We report a case in which dehydrated hereditary stomatocytosis, pseudohyperkalaemia and perinatal oedema coexisted, and were transmitted en bloc in a dominant fashion. Transfusions did not cure the oedema, that spontaneously receded after a few months. We assume that the various manifestations stemmed from one single altered locus, yet to be determined.