A case of paraneoplastic hypercalcaemic syndrome is reported in a patient with Hodgkin's disease. This was detected eight months before widespread lymphadenopathy became apparent. Lymphocyte depleted Hodgkin's disease was diagnosed. PTH (parathyroid hormone) activity was suppressed and PTHRP (PTH related protein) was less than 5 pmol/l. 1,25(OH)2D3 was in the normal range. Plasma calcium values returned to normal after the administration of indomethacin. Thus the pathogenesis of the hypercalcaemia in this patient could be associated with the synthesis of prostaglandins.