BACKGROUND As primary hyperparathyroidism affects mainly middle-aged and elderly women, it is an infrequent finding during gestation and breastfeeding. To date, less than 200 pregnant patients with primary hyperparathyroidism diagnosed during pregnancy have been described. Like in other disorders of the parathyroid gland, the recognition of primary hyperparathyroidism during pregnancy and lactation may be difficult, as clinical symptoms are not specific, while laboratory findings may be masked by some typical pregnancy-induced changes in calcium and phosphate homeostasis. If remains untreated, the disease may result in serious clinical implications for the mother and fetus. Most authors consider surgery within the second trimester of pregnancy as the treatment of choice in this group of patients. METHODS In our paper, we discuss the case of a 35-year-old female with a history of recurrent acute pancreatitis and recurrent abortions. As the patient declined surgery, conservative management with calcitonin was started and continued throughout the rest of pregnancy, and led to giving birth to the infant whose only health problem was transient hypocalcemia. CONCLUSIONS The described case shows that conservative management, if started respectively early and conducted on the basis of a patient's condition, may effectively reduce increased perinatal and maternal morbidity and mortality in pregnant women declining surgery.