A hand tool with an illuminating device includes a handle having a receiving space defined therein. A holding seat is received in the receiving space. The holding seat has a battery chamber defined therein, a shank chamber defined therein, and a plurality of bit holders formed thereon. A tool set is received in the holding seat. The tool set includes a plurality of tool bits detachably held in the bit holders and a tool shank detachably received in the shank chamber. The tool shank has a coupling portion extending therefrom and a connecting portion formed thereon for detachably connecting to any one of the tool bits. An illuminating device is received in the receiving space and electrically connected to the holding seat. The illuminating device has a coupling slot defined axially therein for engaging with the coupling portion of the tool shank.