Abstract: A roller chain-connecting tool comprises a narrow elongated body containing a lengthwise-extending threaded rod journaled in and extending through both ends of the body to hexagonal bolt heads for rotating the rod. A chain hook is mounted on the threaded rod by means of an internally threaded block which moves lengthwise along the tool's body when the rod is turned. In one embodiment, a second chain hook is mounted on one end of the body and the rod is threaded in only one direction. In another embodiment, the second chain hook is mounted on another internally-threaded block and the threaded rod has approximately one half threaded in each direction from its center. The chain hooks or jaws are gently curved toward one another and are tapered so as to fit both small and large gauge roller chains, the large chains being at least twice the size of the small chains.