Parathyroid hormone (PTH) is a hormone produced by the parathyroid glands that regulates calcium and phosphate metabolism in the body. Magnesium is an essential mineral that plays a role in many cellular processes, including nerve and muscle function, DNA synthesis, and bone health. This review aims to examine the association between PTH and magnesium in health and disease states. Several studies have shown that lower levels of magnesium in the blood are associated with higher levels of PTH. This association has been observed in both healthy individuals and those with chronic kidney disease, primary hyperparathyroidism, and vitamin D deficiency. The mechanism by which magnesium regulates PTH synthesis is not yet fully understood but appears to involve magnesium’s role in the calcium-sensing receptor (CaSR) and cellular signaling pathways. In conclusion, the evidence suggests a clear and significant association between PTH and magnesium, with lower serum magnesium levels associated with elevated PTH levels. Further research is needed to understand clinical practice’s underlying mechanisms and implications.