1. Convulsions causing fractures complicated the post-operative course of two patients after parathyroidectomy.

2. One patient with primary hyperparathyroidism and osteitis fibrosa developed tetany which was controlled with difficulty with the usual measures to correct hypocalcaemia. The convulsion occurred during hypomagnesaemia. This seemed the main immediate cause of symptoms and was easily corrected when recognised.

3. The second patient had been subjected to total parathyroidectomy for treatment of renal glomerular osteodystrophy. The complications were entirely due to hypocalcaemia and the usual treatment was inadequate until oral aluminium hydroxide was given.

4. Further experience shows that aluminium hydroxide can be a valuable addition to other measures for dealing with hypocalcaemia due to the "hungry bones" phenomena.