To provide a cowl part structure of a vehicle capable of simplifying the shape of the end part of a cowl top garnish in the vehicle width direction to improve the moldability of the cowl top garnish, and reducing the number of components.

The cowl part structure of the vehicle includes: the cowl top garnish 3; and a cowl top garnish side 10 closing a gap between the side part of a windshield 2 and a side part body panel. The end part of the cowl top garnish side 10 on the vehicle front side Fr is extended to the vehicle front side Fr rather than the side part lower end of the windshield 2, and a vertical wall 11 closing a lateral opening of a cowl box is formed on the end part of the cowl top garnish side 10 on the vehicle front side Fr.