Abstract: A grommet including an elastic grommet body and a clamp, the grommet body having a cylindrical portion for closely receiving an outer periphery of a wire bundle, a flange provided at one end of the cylindrical portion, an annular groove formed on an inner face of an outer peripheral portion of the flange and a seal lip projecting from a distal end of the annular groove such that a seal lip clamping portion of the clamp is fitted into the annular groove, the grommet body comprising: an outer peripheral wall which extends axially from an outer peripheral edge of the flange; and a wall portion which is bent radially inwardly from a distal end of the the outer peripheral wall such that the annular groove is defined by the flange, the outer peripheral wall and the wall portion; the seal lip projecting from a distal end of the wall portion; the flange having a large thickness, while the outer peripheral wall has a thickness smaller than that of the flange; wherein when the seal lip has been turned up over the flang