A suspension arm mounting structure comprises: an arm body section (14) which is disposed between a wheel and a vehicle body and which is configured from a plate-shaped member; a rubber elastic body (46) which is provided between the arm body section (14) and the vehicle body; and a shaft section (16) which is extended from the arm body section (14) in the front-rear direction of the vehicle, is press-fitted or fitted in the through-hole (48) of the rubber elastic body (46), and has a tube-like shape or a closed cross-sectional shape. The shaft section (16) has a pressing section (52) which causes both end surfaces of the plate-shaped member to face each other and press against each other so that the opposing end surfaces are in contact with each other so as to press against each other.