A protective circuit module and a secondary battery including the same. The secondary battery includes: an electrode assembly, a can to house the electrode assembly, and a cap assembly to seal an opening of the can. The protective circuit module includes: a first module electrically connected to the cap assembly; a second module electrically connected to a closed end of the can; and a third module electrically connecting the first module and the second module. The first module includes a mounting portion that is disposed in a groove between the can and the cap assembly.