Hypercalcaemia is a common complication of malignancy. When severe, if treatment is thought to be justified, it should be treated with 2-3 litres of intravenous fluids per day combined with administration of an intravenous bisphosphonate drug. Mild to moderate hypercalcaemia is more difficult to manage satisfactorily. Oral steroids can be tried but are often ineffective, oral phosphate is effective but causes side-effects. It is likely that active oral bisphosphonate drugs will soon be available and these are likely to become the treatment of choice.