Introduction Asymptomatic mild primary hyperparathyroidism is increasingly being identified during pregnancy. Recent studies have demonstrated inconsistent findings with regard to pregnancy complications and the need for surgical intervention during pregnancy. Method A retrospective audit of outcomes of pregnancies complicated by hypercalcaemia over a 15-year period was performed. Results Twenty-nine pregnancies to 26 women with hypercalcaemia were identified, corresponding to 37 cases per 100,000 deliveries. Hypercalcaemia was due to primary hyperparathyroidism in 90% of cases, with mean serum calcium of 2.89 mmol/l and mean ionised calcium 1.43 mmol/l. Four women underwent successful neck exploration during pregnancy. Pregnancy complications were limited to three cases of pre-eclampsia and one case of symptomatic neonatal hypoparathyroidism. Conclusion Close observation without surgical intervention would seem reasonable in women with mild hypercalcaemia during pregnancy.