We present a case of primary hyperparathyroidism with severe hypercalcaemia, treated successfully with ultrasound (US) guided percutaneous interstitial laser photocoagulation (ILP) of a single parathyroid tumour. To our knowledge, this is the first reported case of ILP applied in primary hyperparathyroidism. US guided thermic tissue coagulation with ILP may be a nonsurgical alternative in patients with symptomatic hypercalcaemia due to a parathyroid tumour when surgery is contraindicated.