Parathyroidectomy: Surgical removal of one or more of the parathyroid glands. Parathyroidectomy is usually done to treat hyperparathyroidism. Primary hyperparathyroidism is the most common disorder of the parathyroid glands, and is characterized by an elevation in the blood levels of calcium, loss of calcium from the bones, and an elevation of the parathyroid hormone level (PTH). Secondary hyperparathyroidism is usually the result of kidney failure. Surgery remains the only effective treatment for hyperparathyroidism.