To provide a grommet for a wire harness in which a retention force of a wire-harness grommet is strengthened to prevent a grommet mounted onto a penetration hole of a vehicle-body panel from coming off the penetration hole.

The grommet is externally fitted onto a wire harness to be wired within a vehicle, and is mounted onto a penetration hole of a vehicle-body panel. It includes a small diameter cylindrical part that is molded with rubber or elastomer and has the wire harness inserted therethrough in tight adhesion, a pleated diameter-direction protrusion part protruded from an outer circumference position of an intermediate part in the longitudinal direction of the small diameter cylindrical part towards the outer diameter direction, and an outer-circumference cylindrical part that is continuous to the outer circumference end of the diameter-direction protrusion part. The outer-circumference cylindrical part is made to be a cone-shaped cylinder, connects with the diameter-direction protrusion part at the intermediate part in the longitudinal direction thereof, and a circular vehicle-body latching recess-section is formed on an outer circumference face of the outer-circumference cylindrical part at the diameter-expansion side thereof, and the diameter-contraction side thereof is made to be a thick part having the thickness thereof to be thicker than the diameter-direction protrusion part.