In contrast to the relatively early flowering of organotransition-metal chemistry (1955 to the present), the corresponding development of actinide organometallic chemistry has taken place largely within the past 15 or so years. During this period, 5f organometallic science has blossomed, and it is now apparent that the actinides have a rich, intricate, and highly informative organometallic chemistry. Intriguing parallels to and sharp differences from the d-block elements have emerged. Actinides can coordinate the organic active groups or bind to carbon by the covalent bonds.