Gitelman syndrome (GS) is an autosomal-recessive condition characterized by hypokalaemia, hypomagnesaemia and hypocalciuria. Though it affects women of child-bearing age very little information is available about its impact on maternal and fetal outcome. We describe the course of pregnancy in a patient with GS which was characterized by a sixfold increase in potassium and magnesium requirements with inability to achieve normal levels despite intravenous supplementation. There was no adverse impact on the course of pregnancy or fetal outcome. The case highlights the variability in the phenotypic presentation of GS and recommends frequent monitoring of electrolytes with supplementation guided by clinical requirements without aiming to achieve normal blood levels.