There is obtained a parting portion structure for a vehicle that can enhance the rigidity of one end of a design panel that constitutes a parting portion, while imparting a feeling of sharpness to the parting portion. An end edge portion of an upper-end rear portion of a fender panel is folded back toward the opposite side of a design surface and superimposed thereon. A return line of the end edge portion is arranged adjacent to a linear second ridgeline of a side outer panel, and linearly extends along the second ridgeline. Besides, superimposed regions of the end edge portion are joined to each other by an adhesive.