Hypermagnesemia is a rare condition that commonly follows excessive therapeutic administration of magnesium sulfate to treat eclampsia of pregnancy. Signs and symptoms of this condition include extreme muscle weakness, loss of deep tendon reflexes, mental status depression, and cardiac dysrhythmias. Clinically significant hypermagnesemia following oral or rectal administration of magnesium containing products in patients with normal renal function is rare. We report a case of hypermagnesemia following massive Epsom salt ingestion that resulted in extreme musculoskeletal weakness and altered mentation.