The discovery of radium, its physical and chemical characteristics, production, toxicity and health hazards are described. Its occurrence in nature, detection, separation and measurement along with its uses, applications and importance from scientific and technical stand points are listed. This account of radium is given on the 100 years of the discovery of radium by Madam Curie and her husband Pierre Curie in 1898. In 1911 she was awarded Nobel Prize in Chemistry for her discovery of polonium and radium.