Primary hyperparathyroidism in pregnancy is rare, with a reported incidence of 1%. It is often asymptomatic with the majority of cases in case-series identified incidentally. Published case series report dramatic maternal complications including nephrolithiasis, pancreatitis, hyperemesis gravidarum, pre-eclampsia and hypercalcaemic crises with fetal complications including intrauterine growth restriction, preterm delivery and neonatal hypocalcaemic tetany. Severity of complications appears proportional to the calcium concentrations though data are limited. In milder cases, plasma calcium levels may be monitored regularly and managed conservatively with adequate fluid intake. In case of very high and increasing calcium levels, and in symptomatic cases, surgical intervention may be indicated. This should be performed in the second trimester if possible. Investigations, differential diagnosis and management will be discussed with illustration from recent cases managed in our antenatal clinics.