A massaging device includes a housing having a chamber and a mouth communicating with the chamber of the housing for filling a fluid into the chamber of the housing, and a cover engaged with the mouth of the housing for enclosing the chamber of the housing and for retaining the fluid within the chamber of the housing and for preventing the fluid from flowing out of the chamber of the housing. The housing includes a number of peripheral protrusions for forming one or more peripheral recesses. The cover includes one or more depressions for forming a knob. The housing includes a casing extended into the housing, and the casing includes an inner end portion engaged with the cover.
