A 16 year old male developed symptomatic hypercalcaemia of immobilization on day 47 following a diving accident which had resulted in incomplete C4 tetraplegia. Following initial reduction in serum calcium with salmon calcitonin 100 U/day, symptomatic hypercalcaemia recurred. A single dose of 30 mg pamidronate sodium, given intravenously, caused serum calcium to fall within 48 hours. Initial mild, asymptomatic hypocalcaemia was followed by a return to sustained normocalcaemia. No major adverse reaction was encountered, and if further clinical experience confirms its efficacy, pamidronate sodium will warrant consideration as first-line therapy for immobilization hypercalcaemia.