A reinforcing construction for rear wheel housings in automobiles, provided on the right and left sides of a car body, which comprises a connection member (24) having engagement portions at two axial ends thereof, respectively, and extending between right and left suspension towers, a first restraint device (26) mounted on one of the right and left rear wheel housings for restraining one of the two engagement portions on the connection member, and structures mounted on the other of the right and left rear where housings for restraining the other of the two engagement portions. The first restraint device comprises two lock levers (32, 34) supported independently of each other and swingably on the rear where housings to be capable of releasing and restraining one of the two engagement portions on the connection member, each of the lock levers having an inclined surface (33, 35) which is adapted to come into frictional contact with one of the engagement portions. The two inclined surfaces are inclined such that inclination directions in a widthwise direction of the car body are opposite to each other.