A new clinical classification of the hypertensive disorder of pregnancy is proposed based solely on the physical signs of hypertension and proteinuria (Appendix 1). Hypertension and proteinuria in pregnancy may have a number of different underlying causes with different aetiologies and pathologies. The classification is intended to define meaningful clinical categories by which all cases of hypertension and proteinuria in pregnancy, labour or the puerperium may be classified. The term “hypertensive disorders” is taken to include all disorders or conditions presenting with either or both hypertension and proteinuria in pregnancy. Revised definitions of hypertension and proteinuria are proposed based on standardised methods of measurement with simple criteria of abnormality. (Appendix II). A revised nomenclature is suggested which it is hoped will find general approval and acceptance so that the incidence and the results of treatment of the hypertensive disorders of pregnancy may be compared and mutual understanding achieved.